2. About me
Name: Belew Yenealem (aka. Yared)
Graduated from Addis Ababa Institute
of Technology in Software Engineering.
Currently an instructor at Debre Tabor
University, Computer Science
Department, Ethiopia
Address: belewyenealem@gmail.com
4. Required Text Book
Shelly and Rosenblatt System
Analysis and Design. 3rd
and 8th
edition
Satyinger Jacson Burd. System
analysis ad Design in Changing the
world. 5th editioin
William Amadio System Development
a Practical Approach
5. Course Objective
Understand the design and development
of Computer Based Information System
(CBIS) in an organization.
Know about the various aspects and
components of System Life Cycle in a
CBIS.
Apply the general concept of System
Analysis.
6. Chapter 1: System-Overview
Data, information, knowledge,
wisdom?
What is a System?
What is Analysis?
What is Design?
What is System Analysis?
What is System Design?
What is SAD?
7. Data vs. Information
Data, information, knowledge,
wisdom?
– Data- unorganized/unprocessed/ raw
facts [names, numbers, words, symbols,
signs]
– Information- processed and
contextualized data, meaningful [answers
the questions: what, who, when, where]
8. Data vs. Information
Data, information, knowledge,
wisdom?
– Knowledge- an understanding gained
thru experience. [answers the question:
How
– Wisdom- Applied knowledge
Fact!=data!=information!
=knowledge!=wisdom!=future
9. What is a System?
A collection of parts that work together to
achieve a goal/task
– Examples
• Solar system
• Digestive systems
• Public transport system
• Central heating system
• Computer system
• Information system
an interrelated set of business
procedures (or components) used within
one business unit, working together for
some purpose.
10. Cont?
Elements of System
– Input, Process, and Output
Characteristics of a system
– Components, Interrelated components,
Boundary, Purpose, env’t, interfaces,
constraints, input ,and output
System concepts
– Decomposition, Modularity, coupling,
and Cohesion
13. Characteristics of System
Components— Subsystem –an irreducible
or aggregate parts in a system.
Interrelated components- dependence of
one part of the system to the other
[components are interrelated]
Boundary- the limits of a system,
separating it from other systems.
Purpose – the overall goal/ function of the
system
14. Characteristics of System
Environment— A system exists within an
environment—everything outside the
system’s boundary that influences the
system
Interfaces--Point of contact where a
system meets its environment or where
subsystems meet each other
Constraint– a limit to what a system can
accomplish
15. Characteristics of System
Input – System takes input from its
environment
Output - System returns output to its
environment as a result of its functioning to
achieve the purpose. Output from individual
subsystems may be inputs to other
subsystems.
16. System concepts
Decomposition [ Why?]
– Process of breaking down a system into smaller
components (parts)
Modularity
– Dividing a system up into chunks or
modules of a relatively uniform size.
18. System concepts
Coupling
– System being dependent on other systems,
represents the degree to which a single unit is
independent from others.
Cohesion
– Extent to which a subsystem performs a single
function, represents the degree to which a part
of a system forms a logically single, atomic unit.
19. Approach to system development
There are three strategies of IS
development
1. Process-oriented approach
2. Data-oriented approach
3. Object-oriented approach
20. Process-oriented approach
• An strategy to IS development that focuses on how and
when data are moved through and changed by an IS
[ focuses on Process]
Data-oriented approach
• An strategy to IS development that focuses on the ideal
organization of data rather than where and how data are
used. [ focuses on Data]
Object-oriented approach
• A system development methodologies and techniques
base on objects rather than data or process [ focuses on
Object]
21. Information System?
IS
– An arrangement of information for the
purpose of supporting and improving
data processing [ day to day
operations in a business] and
information services [problem
solving and decision making]
1.14
22. What is an Information Systems?
Interrelated components working
together to
– Collect
– Process
– Store
– Disseminate information
To support decision making,
coordination, control, analysis and
visualization in an organization
24. IS Types
1. Transaction Processing Systems (TPS)
2. Management Information Systems
(MIS)
3. Decision Support Systems (DSS)
4. Expert System and Artificial Intelligence
(ES &AI)
25. Transaction Processing Systems
(TPS)
TPS are computerized information systems that
were developed to process large amounts of
data for routine business transaction.
Automate the handling of data about business
activities and transactions, which can be thought of
a simple discrete events in the life of an
organization.
26. Management Information Systems
(MIS)
Information system at the management level of an
organization that serves the functions of:
– planning, controlling, and decision making by providing
routine summary and exception reports.
It takes the relatively raw data available through a TPS
and converts them into a meaningful aggregated form
that mangers need to conduct their responsibilities.
Developing an MIS calls for a good understanding of
what kind of information managers require and how
managers use information in their jobs.
27. Decision Support systems
(DSS)
DSS are designed to help organizational
decision make decision.
A DSS is composed of a:
– Database ( may be extracted from a TPS/MIS)
– Graphical/mathematical models for business
process
– User interface that provides a way to
communicate with DSS
28. Expert System and Artificial
Intelligence (ES & AI)
A system that emulates the decision-making ability
of a human expert.
Designed to solve complex problems by reasoning
about knowledge, like an expert.
29. Why SAD?
To improve organizational systems through
developing or acquiring application software that
can help employees accomplish key business
tasks more easily and efficiently.
To create and maintain information systems
that perform basic business functions.
30. Individual Assignment(5%)
Describe your university or college
as a system.
– What is the input?
– What is output?
– What is the boundary?
– What is the components and their
relationship?
– The constraint
– The environment
Draw a diagram of this system
32. Managing IS Project
Project
– a planned undertaking of a series of
related activities to reach an objective
that has a beginning and an end.
– a temporary attempt or endeavour
made to produce some kind of a tangible
or intangible result ( a unique product,
service, benefit, competitive advantage,
etc. )
33. Project Management
The science (theory) of:
– organizing all the project components,
– stepping thru all the implementation
stages and phases,
– providing and managing all the
resources,
– protecting the project from potential risks,
– solving problems and managing changes
for the purpose of achieving initial project
goals,
– developing the product, and
– delivering project results
34. Focus of PM
To ensure that system development
projects meet customer expectations
and are delivered within budget and
time constraints.
35. Project Manager
A systems analyst with a diverse set
of skills—management, leadership,
technical, conflict management, and
customer relationship—who is
responsible for initiating, planning,
executing, and closing down a project.
40. Project Phases
Planning (Why build the system?)
Analysis (Who, what when, where
will the system be?)
Design (How will the system
work?)
Implementation (System delivery)
41. Initiation
Assess the size, scope, and
complexity of the project and to
establish procedures to support later
project activities.
42. Planning
focuses on defining clear, discrete
activities and the work needed to
complete each activity within a single
project
43. Planning--WBS
Dividing the project into manageable
tasks
Gantt chart
– A graphical representation of a project
that shows each task as a horizontal bar
whose length is proportional to its time
for completion.
44. Planning - COCOMO
COCOMO
– A method for estimating a software
project’s size and cost.
• To estimate project resources
50. Gantt and PERT
– Gantt chart is a graphical
representation of a project that shows
each task activity as a horizontal bar
who is proportional to its time for
completion.
– PERT chart is a diagram that
represents project activities & their
dependencies
• There are several tools to support Gantt
and PERT charts
51. PERT
a critical path scheduling
technique used for controlling
resources and timing
– PERT = Program Evaluation Review
Technique
– It allows to determines critical path
scheduling and Slack Time
52. Gantt vs. PERT
Gantt
– Visually shows duration of tasks
– Visually shows time overlap between tasks
– Visually shows slack time
PERT
– Visually shows dependencies between tasks
– Visually shows which tasks can be done in
parallel
– Shows slack time by data in rectangles
60. SDLC
Traditional methodology used to
develop, maintain, and replace
information systems.
The SDLC is a phased approach to
analysis and design that holds that
systems are best developed through
the use of a specific cycle of analyst
and user activities.
64. Why SDLC?
SDLC has three primary objectives:
– ensure that high quality systems are
delivered,
– provide strong management controls
over the projects, and
– maximize the productivity of the
systems staff.
65. Chapter 4:
Systems Planning & Selection
an organization’s total information
system needs are identified, analyzed,
prioritized, and arranged.
The process of
– identifying,
– selecting,
– initiating,
– planning projects and
– assessing projects feasibility.
66. Project Identification and
Selection
Identify the need for a system
– Problems in existing system or process
– New feature required in an existing
system
– A new idea for which in Information
System is required
– A requirement to improve efficiency in the
organization
– The need to keep up with competitors
67. Key Sources for IS projects
Managers and business units
IS managers
Formal planning groups
69. Evaluation Criteria
Possible Evaluation Criteria when
classifying and ranking projects
– Value chain analysis= Extent to which activities
add value and costs when developing products
and/or services; information systems projects
providing the greatest overall benefits will be
given priority over those with fewer benefits
– Strategic alignment== Extent to which the
project is viewed as helping the organization
achieve its strategic objectives and long-term
goals
70. Evaluation Criteria cont.
Possible Evaluation Criteria when
classifying and ranking projects
– Potential benefits== Extent to which the project
is viewed as improving profits, customer service,
etc., and the duration of these benefits
– Resource availability== Amount and type of
resources the project requires and their
availability
71. Evaluation Criteria cont.
Possible Evaluation Criteria when
classifying and ranking projects
– Project size/duration==Number of individuals
and the length of time needed to complete the
project
– Technical difficulty/risks ==Level of technical
difficulty to complete the project successfully
within given time and resource constraints
72. Selection
Factors to be considered:
– Perceived and Real needs of the
organization
– Existing systems and ongoing projects
– Resource availability
– Evaluation criteria
– Current business conditions
– Perspective of the decision makers
73. Decision Outcome
From Identification and Selection:
– Accept, Reject, Delay Project
– Refocus Project
– End-User Development
– Purchase System
– Modify and Resubmit
74. Project Initiation and Planning
Transform a vague system
requirements into a tangible project
description
75. The two processes
Initiation
– Assess the size, scope, and complexity of the
project and to establish procedures to support
later project activities.
– Projects are selected, authorized, and chartered
Planning
– focuses on defining clear, discrete tasks and the
work needed to complete each task
76. Outcome of Planning
BPP
– an internal document that contains all information
collected and analyzed during initiation and planning
– reflects the best estimate of the project’s scope,
benefits, costs, risks and resource requirements
SOW
– a short document prepared for the customers that
describes what the project will deliver and outlines
all work required to complete the project
– a useful communication tool that assures that both
system analysts and customers have a common
understanding of the project.
77. What goes into a BPP?
Introduction
System Description
Feasibility Assessment
Management Issues
78. What goes into a SOW?
Scope of the work
Location of the work
Period of performance
Deliverables Schedule
Applicable standards
Acceptance Criteria
Specialized Requirements
79. Feasibility study
an assessment of the practicality of
a proposed plan or method.
an analysis of the viability of an idea.
an analysis of how successfully a
project can be completed
[achievability]
Answer for :“should we proceed with
the proposed project idea?
80. Technical feasibility
To determine whether the company
has the technical expertise ( the
organization’s ability and experience)
to handle completion of the project.
– Transportation
– Business location
– Technology needed and experience
using it
– Materials and labor
81. Economic feasibility
Involves a cost/ benefits analysis.
determine the positive economic
benefits to the organization that the
proposed system will provide.
Worthwhileness
a measure of the cost-
effectiveness of a project or
solution
Provides an economic justification
for the system using cost-benefit
83. Operational feasibility
a measure of how well a proposed
system
– solves the problems, and
– takes advantage of the opportunities
identified during scope definition and
– how it satisfies the requirements
identified in the requirements analysis
phase of system development
84. Scheduling feasibility
a measure of how reasonable the
project timetable is.
Given our technical expertise, are the
project deadlines reasonable?
Timetable and Deadline [cutoff date
] reasonability
a measure of how reasonable the
project timetable is.
87. Systems Analysis
system requirements are studied
and structured.
The process of understanding in
detail what a system should
accomplish.
is the study of a business problem for
the purpose of
– specifying the business requirements
for the solution and
– recommending improvements
88. Analysis
answers the questions of:
– who will use the system,
– what the system will do, and
– where and when it will be used
Goal of Analysis phase
– Truly understand the requirements of
a system
89. Analysis phase
Input:
– Accepted project with baseline project plan and Work of
statement
Output:
– System requirement & best alternatives to design the
system
• Output of phase 3 = Input of phase 4
Purpose:
– How to determine requirements for the potential system?
– How to structure the generated requirement?
– How to select the best alternative design strategy?
Process:
– Requirement determination
– Requirement structuring
90. System Analysis
Determine system requirements
Select appropriate methods to elicit
system requirements from users of
system
– Interviews, focus groups, surveys,
discussions, or other techniques
91. Analysis cont.
Analysis
– Study of current procedures and
information systems
• Determine requirements
– Study current system
– Structure requirements and eliminate
redundancies
• Generate alternative designs
• Compare alternatives
• Recommend best alternative
92. 3 parts of Analysis
Determining Requirements
Structuring Requirements
Selecting best alternative strategy
93. Req’t Determination
more detailed, precise list of what the
new system must do to provide the
needed value to the business
Answer the question: What is the
system to do?
gathering information on what the
system should do from as many
sources as possible.
94. What is Req’t?
a statement of what the system must
do or what characteristics it needs to
have
is a characteristic or feature that
must be included in an information
system to be acceptable to users.
Serves as benchmarks to measure
the overall acceptability of the
finished system.
97. Traditional methods of Req't
gathering: Interviews
planned meeting during which you
obtain information from another
person
98. Interview
An interview is a planned meeting
during which you obtain information
from another person.
Interviewing involves getting people to
recall and convey information they
have.
99. Interview Guidelines
Plan the Interview
– Prepare interviewee by making an
appointment and explaining the purpose
of the interview. Prepare a checklist, an
agenda, and questions.
100. Cont.
Be Neutral
– Avoid asking leading questions [that
suggest or favor a particular reply]
– For example, rather than asking,
• “What advantages do you see in the
proposed system?” you might ask,
• “Do you see any advantages in the proposed
system?”
101. Cont.
Listen and take notes
– Give your undivided attention to the
interviewee and take notes or tape-
record the interview (if permission is
granted).
103. Open Ended Questions
Have no prespecified answers.
allow the respondent open options for
responding
leave room for elaboration on the part
of the interviewee.
104. Closed-ended questions
provide a range of answers from
which the interviewee may choose.
Limit the respondent’s options.
Require a specific answer
Different question forms
– True or False
– Multiple choice
– Rating a response
– Ranking in some order
105. Probes (Probing
questions)==Follow Up
to go beyond the initial answer to get
more meaning, to clarify, and to draw
out and expand on the interviewee’s
point
Probes allow the systems analyst to
follow up on questions to get more
detailed responses.
106. Questionnaires[ኩኩኩኩኩ]
A questionnaire, also called a survey, is a
document containing a number of
standard questions that can be sent to
many individuals.
is a set of written questions [either on
paper or electronic] for obtaining
information from individuals.
a list of questions that several people are
asked so that information can be collected
about something
108. L Choosing Questionnaire
Respondents / Recipients
Select a sample
– Those people who’re willing and
motivated to respond
A random group
– A random selection
A purposeful sample
– Based on some criteria
109. rules for designing a good
questionnaire:
Allow ample white space.
Allow ample space to write or type in
responses.
Make it easy for respondents to
clearly mark their answers.
Be consistent in style.
Avoid:
– Bias, crowded pages, leading questions,
threatening, abbreviations
110. Interviewing vs Questionnaire
Interview is more familiar and
personal than a questionnaire.
During a face-to-face interview, you
can react immediately to anything the
interviewee says but Questionnaire is
passive.
Interviewing, however, is a costly and
time-consuming process.
You seek input form a large group?
Use Questionnaire!
111. Cont.
In contrast, a questionnaire gives
many people the opportunity to
provide input and suggestions
If a question, in a questionnaire, is
misinterpreted, you cannot clarify the
meaning as you can in a face-to-face
interview.
112. Cont.
Interview is quite time intensive and
expensive, but gives rich and detailed
info, easy reaction, more familiar and
personal, good for blinds.
Questionnaire
– Inexpensive, take less time, good for
specific info, gathered info is less rich,
passive, easy for many access, difficult
for clarification if misinterpretation occurs,
good for deafs.
113. Direct Observation
Observation, the act of watching
processes being performed, is a
powerful tool to gain insight into the
as-is system
gather information by watching the
users of the system at work
116. What to find in Documents?
Problems with existing systems (e.g.,
missing information or redundant
steps)
Opportunities to meet new needs if
only certain information or information
processing were available
Values and missions of the org.
Influential stakeholders.
Principles and rules in the org.
117. Types of Documents
Procedures
– How a particular job or task is performed
Business Forms
– What data flows in and out of the system
Reports
– Primary output of current system
– How data is manipulated, transformed
Manuals
– Description of current IS, how to of an
existing system
118. Contemporary Methods
– Joint Application Design
– Rapid Application Design
– Participatory Design
– CASE tools
– Prototyping
They can be used for Req’t
gathering and for system
development model
120. Prototyping
Designing and Building a scaled-
down version of the desired
information system.
A prototype is an early working
version of an information system.
A small-scale, incomplete, but
working sample of a desired
system.
a rudimentary version of an IS based
on user feedback.
124. Advantages of Prototyping
Reduce time and costs
– the early determination of what the user
really wants can result in faster and less
expensive software
– the potential for changing the system
early in its development,
– the opportunity to stop development on a
system that is not working,
Captures Req’t in concrete forms
125. Contd.
Improved and increased user
involvement [It involves the user in
analysis and design]
– prevents many misunderstandings and
miscommunications
– Better feedback and specifications
– User’s satisfaction
– are useful in seeking user reactions,
suggestions, innovations, and revision
plans
– Users can easily visualize the system
from the very beginning
126. Disadvantages of Prototyping
Insufficient Analysis
User confusion of prototype with final
version
Excessive development time of
Prototype
Developer attachment to prototype
Tendency to avoid formal
documentation
127. Process of Prototyping
Identify basic requirements
– Determine basic requirements including
the input and output information desired
130. Contd.
Revise and enhance the prototype
– Using the feedback both the
specifications and the prototype can be
improved. Negotiation about what is
within the scope of the contract/product
may be necessary. If changes are
introduced then a repeat of steps #3 and
#4 may be needed.
131. When to use it?
User requests aren’t clear
Few users are involved in the system
– Couse few won’t give detailed Req't
Designs are complex and require
concrete form
There was communication problems
between analysts and users
Tools are readily available to build
prototype
132. L Reading Assignment
Dimensions of Prototyping
Horizontal and Vertical
Types of Prototyping
– Throwaway
– Evolutionary
– Incremental
– Extreme
134. L Types of CASE tools
depending on where in the
development process they are most
involved in:
– Upper—support analysis and design
phases
– Lower—support coding phases
[Implementation]
– Integrated—all phases.
136. L Benefits : CASE Tools
Tasks are much faster to complete and
alter
Development information is centralized
Information is illustrated through
diagrams, which typically are easier to
understand
Reduce maintenance costs, improve
software quality, and enforce discipline
To assess the magnitude of changes to
the project.
137. JAD-Joint Application Design
A structured process in which users,
managers, and analysts work
together [hence Joint] for several
days in a series of intensive meetings
to specify or review system
requirements.
A means to bring together the key
users, managers, and systems
analysts involved in the analysis of a
current system.
138. Purpose: Why JAD?
To collect systems requirements from
the key people involved with the
system.
Allows analysts to see the areas of
agreement and the areas of conflict.
To have Shared Understanding
When users participate in the systems
development process, they are more
likely to feel a sense of ownership in
the results, and support for the new
system.
139. L JAD
In this approach, the sponsor company
creates a task force of users, managers,
and IS professionals that works together
to gather information, discuss business
needs, and define the new system
requirements. This group usually meets
over periods of days or weeks.
140. typical JAD participants
JAD Session Leader
– Plans and leads JAD sessions
– Organizes and runs the JAD
– Sets the agenda and sees that it’s met
– Remains neutral on issues & doesn’t
contribute ideas or opinions
– Concentrate on keeping the group on
agenda, resolving conflicts and
disagreements, and soliciting all ideas
143. RAD-Rapid Application
Development
Why Prototyping, CASE, JAD?
– -To facilitate development
– To support RAD
To radically decrease the time needed
to design and implement information
systems.
Involves: extensive user
involvement, prototyping, JAD
sessions, integrated CASE tools,
and code generators.
144. RAD Emphasis
The emphasis in RAD is generally less on
the sequence and structure of processes
in the life cycle and more on doing
different tasks in parallel with each other
and on using prototyping extensively.
The main objective of all RAD
approaches is to cut development time and
expense by involving users in every phase
of systems development.
145. WHEN TO USE RAD
Consider using RAD when:
– 1. Your team includes programmers and analysts
who are experienced with it; and
– 2. There are pressing business reasons for speeding
up a portion of an application development; or
– 3. When you are working with a novel ecommerce
application and your development team believes that
the business can sufficiently benefit over their
competitors from being an innovator if this
application is among the first to appear on the Web;
or
– 4. When users are sophisticated and highly engaged
with the organizational goals of the company
146. Disadvantages of RAD
May try and hurry the project too
much
Loosely documented
May not address pressing business
problems
Potentially steep learning curve for
programmers inexperienced with RAD
tools
147. Cont.
The accelerated time cycle might
allow less time to develop quality,
consistency, and design standards.
148. PD-Participatory Design
Originally Co-operative design, now
often co-design
– is an approach to design attempting to
actively involve all stakeholders (e.g.
employees, partners, customers, citizens,
end users) in the design process to help
ensure the result meets their needs and
is usable.
149. L JAD vs PD
They are two established user
involvement methodologies.
JAD is a practitioner-derived
methodology focusing on structured,
facilitated meetings through which
user involvement is elicited in systems
development. PD stresses the social
context of the workplace in workshops
in which designers and workers
collaborate in design and
development activities.
150. Cont.
Pont of Comparison JAD PD
Criteria for Validation Quantitative:
economic optima, time
savings, performance
indices
Qualitative:
democracy, mutual
learning, mutual
education, conflict
resolution
Goal Improved System Improved Workplace
151. BPR
The Search for, and implementation
of, radical change in business
processes to achieve breakthrough
improvements in products and
services.
a process in which existing methods
of doing business are replaced with
new and updated methods
152. Cont.
The overall process by which current
methods are replaced with radically
new methods is referred to as
business process reengineering
(BPR).
153. Deliverables and Outcomes
Deliverables for Req’t determination
– From interviews and observations
• Interview transcripts, observation notes,
meeting minutes
– From existing written documents
• Mission and strategy statements, business
forms, procedure manuals, job descriptions,
training manuals, system documentation,
flowcharts
– Form Computerized sources
• JAD session results, CASE repositories,
reports from existing systems, displays and
reports from system prototype
154. Structuring Req’t
Organizing a gathered Req't into a
form that is a meaningful
representation of the existing system.
Structuring taking the system
requirements you find during
requirements determination and
ordering them into tables,
diagrams, and other formats that
make them easier to translate into
technical system specifications.
155. Two Stages
Process Modeling
– graphically representing the processes
– Use DFD—shows mov’t of data
– Logic Modeling==shows internal
structure and functionalities of the
processes in DFD
Conceptual Data Modeling
– Shows data in a system
– ER diagram—show how data is
organized in a system.
158. DFD
Shows how data moves thru an IS
but doesn’t show program logic or
processing steps.
159. Select Best design Strategy
Two basic steps
– 1. generating a comprehensive set of
alternative design strategies
– 2. Selecting the one that is most likely to
result in the desired information system,
given all of the organizational, economic,
and technical constraints that limit what
can be done.
160. Who’s System Analyst
The organizational role most
responsible for the analysis and
design of ISs
the person in the organization most
involved with systems analysis and
design
162. Chapter 6:
Systems Design
a description of the recommended
solution is converted into logical and
then physical system specifications.
Process of defining the architecture,
components, modules, interfaces, and
data for a system to satisfy specified
requirements.
The design phase of the SDLC uses
the requirements that were gathered
during analysis to create a blueprint
163. System Design
the determination of the overall
system architecture—
– consisting of a set of physical processing
components, hardware, software, people,
and the communication among them—
that will satisfy the system’s essential
requirements.
165. Activities in Design Phase
After detailed analysis, Determine
preferred system acquisition
strategy(make, buy, or outsource)
Design the architecture for the system
[Architecture Design]
Make hardware and software selections
[Hardware and software specification]
Design system navigation, inputs and
outputs [Interface design]
166. Input Design
Input mechanisms facilitate the entry of
data into the computer system, whether
highly structured data, such as order
information (e.g., item numbers,
quantities, costs), or unstructured
information (e.g., comments).
Input design means designing the screens
used to enter the information, as well as
any forms on which users write or type
information (e.g., time cards, expense
claims).
167. Basic Principles in ID
Goal of ID
– To capture accurate information for the
system simply and easily.
The fundamental principles for input
design reflect the nature of the inputs
(whether batch or online) and ways to
simplify their collection
168. Principles
1. Use Online and Batch
Processing Appropriately
– Two general approaches for entering
inputs into a computer system:
• online processing and
• batch processing.
169. Online (Transaction)
processing
each input item (e.g., a customer order, a
purchase order) is entered into the system
individually, usually at the same time as the
event or transaction prompting the input.
– E.g., When you borrow a book from the library, buy
an item at the store, or make an airline reservation,
the computer system that supports each process uses
online processing to immediately record the
transaction in the appropriate database(s).
170. Batch Processing
all the inputs collected over some
period are gathered together and
entered into the system at one time in
a batch.
171. Principles
2. Capture Data at the Source
– Perhaps the most important principle of
input design is to capture the data in an
electronic format at the original source or
as close to the original source as
possible.
176. Types of Outputs
Internal outputs stay inside the system
to support the system's users and
managers
External outputs leave the system to
trigger actions on the part of their
recipients or confirm actions to their
recipients
– Turnaround outputs are those which are
typically implemented as a report eventually
re-enters the system as an input
177. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Principles & Guidelines for Output Design
Types of Outputs
– There are two basic types of computer
outputs, external and internal.
• External outputs leave the system to trigger
actions on the part of their recipients or confirm
actions to their recipients.
– Most external outputs are created as preprinted
forms that are designed and duplicated by forms
manufacturers for use on computer printers.
– Some external outputs are designed as turnaround
documents.
• Turnaround outputs are those which are typically
implemented as a form eventually reenters the
system as an input.
178. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
SoundStage Entertainment Club
Fax 317-494-0999
The following number must appear on all related correspondence,
shipping papers, and invoices:
P.O. NUMBER: 712812
To: Ship To:
SoundStage Entertainment Club SoundStage Entertainment Club
2625 Darwin Drive Shipping/Receiving Station
Indianapolis, IN 45213 Building A
2630 Darwin Drive
Indianapolis, IN 45213
P.O. DATE REQUISITIONER SHIP VIA F.O.B. POINT TERMS
5-3-96 ldb ups N30
QTY DESCRIPTION UNIT PRICE TOTAL
10000 Powder - VHS 19.99 199,900.00
5000 Now and Then - VHS 15.95 79,750.00
2500 Pulp Fiction Soundtrack - CD 7.99 19,975.00
450 U2 on Tour - T-shirt 3.49 1,570.50
Subtotal 301,195.50
Tax 15,059.77
Total 316,255.27
1. Please send two copies of your invoice.
2. Enter this order in accordance with the prices, terms, delivery method, and
specifications listed above.
3. Please notify us immediately if you are unable to ship as specified.
Madge Worthy 5- 4- 96
Authorized by Date
179. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Invoice No. 301231
Name Carlina Smith Date 7/21/97
Address 3019 Duroc Drive Order No. 346910
City Little Rock State AR ZIP 42653
Phone 502-430-4545 Payment Amt
Detach and return top portion with payment
Qty Description Unit Price TOTAL
1 Star Wars - Empire Strikes Back VHS $19.99 $19.99
1 Eric Clapton Unplugged CD $13.99 $13.99
1 Alladin VHS $17.95 $17.95
SubTotal $51.93
Shipping & Handling $7.00
Cash Taxes $2.95
Check
Credit Card TOTAL $61.88
Name
CC # Office Use Only
Expires
RETURN TOP PORTION WITH PAYMENT
SoundStage
Entertainment Club
2630 Darwin Drive - Bldg B
Indianapolis, IN 45213
317-496-0998 fax 317-494-0999 INVOICE
Payment Details
Customer
Please return top portion invoice with payment. Make checks payable to:
SoundStage Entertainment Club.
180. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Principles & Guidelines for Output Design
Types of Outputs
– There are two basic types of computer
outputs, external and internal.
(continued)
• Internal outputs stay inside the system to
support the system's users and managers.
– Internal outputs fulfill management reporting and
decision support requirements.
• Management information systems typically
produce three types of reports: detailed,
summary, and exception.
181. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Principles & Guidelines for Output Design
Types of Outputs
– Internal Outputs (continued)
• Detailed Reports:
– Present information with little or no filtering or
restrictions.
– Some detailed reports are historical in nature.
– Detailed reports confirm and document the
successful processing of transactions and serve as
an audit trail for subsequent management inquiry.
• These reports assist management planning and
controlling by generating schedules and
analysis.
– Other detailed reports are regulatory, that is, required
by government.
182. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Page 1
SOUNDSTAGE ENTERTAINMENT CLUB
− Products Ordered on 6-31-1996 −
PO Number Product Number Product Type Quantity In Stock Quantity On Order
112312 102774 Merchandise 273 450
202653 Title 75 325
393752 Title 251 125
112313 109833 Merchandise 0 200
111340 Title 46 150
231045 Title 225 1,500
253967 Title 332 850
112314 287904 Title 0 2,000
699034 Merchandise 0 300
836785 Merchandise 35 175
984523 Title 213 250
183. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Principles & Guidelines for Output Design
Types of Outputs
– Internal Outputs (continued)
• Summary Reports:
– Categorize information for managers who do not
want to wade through details.
– The data for summary reports is typically
categorized and summarized to indicate trends
and potential problems.
– The use of graphics (charts and graphs) on
summary reports is also rapidly gaining
acceptance because it more clearly summarizes
trends at a glance.
184. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Page 1
SOUNDSTAGE ENTERTAINMENT CLUB
− Product Sales Summary as of 7-2-1996 −
Product Type Product Category Current Month’s Unit Sales Current Year Unit Sales
Merchandise Clothing 784 4,312
Media Accessory 541 2,079
Total:
Title Audio 3,815 20,175
Game Title 1,247 5,671
Video Title 2,136 9,032
Total:
185. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Principles & Guidelines for Output Design
Types of Outputs
– Internal Outputs (continued)
• Exception Reports:
– Filter data before it is presented to the manager
as information.
– Exception reports only report exceptions to
some condition or standard.
186. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Page 1
SOUNDSTAGE ENTERTAINMENT CLUB
− Delinquent Member Accounts as of 7-9-1996 −
− (90 Days Overdue) −
Number Name Area Code Phone Extension Balance Due
137842 Joe Dunn 317 490-0012 111 29.43
142314 Bob Fischer 501 282-7996 43.97
157723 Mary Slatter 218 993-9091 56.99
209438 Harold Martin 823 231-8355 33.17
237121 Kevin Ditmano 655 219-0988 99.23
384563 Rick Carlina 501 454-6311 11.23
421134 Barb Kitts 393 789-5412 231 23.66
476688 Kenny Bum 443 234-8845 123.77
187. Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. Bentley
Principles & Guidelines for Output Design
Output Media and Formats
– A good systems analyst will consider all
available options for implementing an
output, especially output medium and
output format.
• A medium is what the output information is
recorded on, such as paper or video display
device.
• Format is the way the information is displayed
on a medium for instance, columns of numbers.
– The selection of an appropriate medium
and format for an output depends on how
188. Types of Outputs
Detailed Reports:
– Present information with little or no filtering or
restrictions.
– Some detailed reports are historical in nature.
– Detailed reports confirm and document the successful
processing of transactions and serve as an audit trail
for subsequent management inquiry.
Exception Reports:
– Filter data before it is presented to the manager as
information.
– Exception reports only report exceptions to some
condition or standard.
189. Basic Principles
The goal of the output mechanism is
to present information to users so that
they can accurately understand it with
the least effort.
The fundamental principles for output
design reflect how the outputs are
used and ways to make it simpler for
users to understand them.
190. Principles
1. Understand Report Usage
– Understand how reports are used.
• Real time reports
• Batch reports
2. Manage Info load
3. Minimize Bias
194. Data Storage Formats
Types
– Files
• Electronic lists of data that have been
optimized to perform a particular transaction.
– Database
• a collection of groupings of information that
are related to each other in some way (e.g.,
through common fields).
197. Purpose of designing Logical
DB
To structure the data in stable structures
Minimal redundancy
To meet actual data requirements of the
system
To ease physical database design
199. Primary Key
Uniquely identifies a record in a table
Cannot accept null values
A table typically has a column or combination of
columns that contain values that uniquely
identify each row in the table. This column, or
columns, is called the primary key (PK) of the
table and enforces the entity integrity of the
table. Because primary key constraints
guarantee unique data, they are frequently
defined on an identity column.
201. Normalization
used to produce a data model that
has the properties of
– simplicity,
– non-redundancy and
– minimal maintenance.
202. Referential Integrity
a property of data which, when
satisfied, requires every value of
one attribute (column) of a relation
(table) to exist as a value of another
attribute (column) in a different (or
the same) relation (table)
204. Group Assignments / 5%
Briefly Discuss about the following
Concepts:
– Logical and Physical Database
– How to design a logical Database and a
physical database?
– Relational database model
– Primary key and foreign key
– Normalization
– Referential Integrity
– Dependency
205. Chapter 7:
Systems Implementation and
Maintenance
the information system is coded,
tested, installed and supported in
the organization.
206. System implementation
is the construction, installation and
testing of system components and the
delivery of the system for day-to-day
operation.
Expensive phase
Time consuming
– So many people involved
210. 1. Coding
turning the physical design
specifications created at the design
stage into working computer code
by programmers.
Coding is the process of turning
program logic into specific instructions
that the computer system can
execute. Working from a specific
design, a programmer uses a
programming language to transform
program logic into code statements.
211. 2. Testing
Static and dynamic testing
Whether code is executed or not
Automated and manual testing
– Whether testing is done manually or not
213. Inspection
participants manually examine code
for occurrences of well-known errors.
Syntax, grammar and some other
routine errors can be checked by
automated inspection software, so
manual inspection checks are used for
more subtle errors.
Exactly what the code does is not
investigated in an inspection.
215. Desk-checking
A testing technique in which the
program code is sequentially executed
manually by the reviewer.
A manual (non-computerized)
technique for checking the logic of an
algorithm.
219. System Testing
testing of the IS as a whole (as a
complete entity)
The bringing together for testing
purposes of all the programs that a
system comprises.
220. Stub Testing
A technique used in testing modules,
especially where modules are written
and tested in a top-down fashion,
where a few lines of code are used to
substitute for subordinate modules.
Stubs are two or three lines of code
written by a programmer to stand in
for the missing modules
221. Acceptance Testing by Users
Acceptance Testing
– The process whereby actual users test a
completed information system, the end
result of which is the users’ acceptance
of it once they are satisfied with it.
testing the system in the environment
where it will eventually be used
222. 3. Installation
Called System conversion
The process of moving from the
current information system to the new
one
The organizational process of
changing over from the current
information system to a new one
223. Installation
Strategies/approaches
Direct Installation [Abrupt cut-over]
– old system is terminated on a specific
date and the new system is placed into
operation.
– High risk approach
Changing over from the old
information system to a new one by
turning off the old system when the
new one is turned on.
224. Cont.
Parallel Installation
– both the old and new systems are
operated for some time period
– Old and new systems coexist
Running the old information system
and the new one at the same time
until management decides the old
system can be turned off.
running the old system and the new
system at the same time, in parallel.
225. Cont.
Phased Installation
– Changing from the old information
system to the new one incrementally,
starting with one or a few functional
components and then gradually
extending the installation to cover the
whole new system
Staged, incremental, gradual, based
on system functional components
226. Cont.
Single location installation [Pilot
Installation/Operation]
– involves implementing the complete new
system at a selected location of the
company.
– Trying out a new information system at
one site and using the experience to
decide if and how the new system should
be deployed throughout the organization.
227. 4.Documentation
Documentation describes an
information system and helps the
users, managers, and IT staff who
must interact with it. Accurate
documentation can reduce system
downtime, cut costs, and speed up
maintenance tasks
228. Types of Documentation
System Documentation
– detailed information about a system’s
design specifications, its internal
workings, and its functionality.
– describes the system’s functions and
how they are implemented.
– is a by-product of the systems analysis
and design process and is created as the
project unfolds.
229. Types cont.
User Documentation
consists of written or other visual
information about an application
system, how it works and how to use it
Reference guide, user’s guide,
release description, system admins
guide, acceptance sign-off
230. 5. Training
The educational process in which
systems analysts engage in to bring
about the smooth transition from the
old system to the new is called
training.
231. Issues to consider
Who to Train?
– anyone whose work is affected by the
new information system
– All users [both primary and secondary]
• From data entry personnel to decision
makers
Who be Trainers?
– Vendors
– Systems analysts
– External paid trainers
232. Issues to consider
What to Train?
– Use of system
– General computer concepts
– IS concepts (batch Vs. online processing)
– Organizational practice concepts ( e.g.
FIFO inventory accounting)
– System management (e.g. how to
request changes to a system)
– System installation
233. Types of Training Methods
Formal courses —several people
taught at the same time
Resident expert
E-learning/distance learning
Blended learning (combination of
instructor-led training and e-learning)
Software help components
Tutorial ---one person taught at a
time
234. 6. User Support
an ongoing technical support provided
to users
Providing ongoing educational and
problem-solving assistance to
information system users.
User support in an organization is
usually provided in two forms:
– an information center and
– a help desk.
235. 7. Maintenance
Is the process of refining the system
to make sure it continues to meet
business needs.
236. Types of Maintenance
Corrective
– To fix errors and problems
– diagnoses and corrects errors in an
operational system
– repair defects in the design, coding, or
implementation of an IS.
237. Types of Maintenance
Adaptive
– Adds new capability and
enhancements
– involves making changes to an
information system to evolve its
functionality to changing business needs
238. Types of Maintenance
Perfective
– Improving efficiency, reliability, or
maintainability
– involves changes made to a system to
reduce the chance of future system
failure.
239. Types of Maintenance
Preventive
– reduces the possibility of future system
failure.
– Avoids future problems
– Detailed analysis of areas where troubles
are likely to occur.
240.
241. Processes and Deliverables
Process Product
Planning
Analysis
Design
Implementation
Project Plan
System Proposal
System
Specification
New System and
Maintenance Plan
242. SDLC criticisms…
Reliance on the life cycle approach
forced intangible and dynamic
processes such as analysis and
design into timed phases that were
doomed to fail. (martin, 1999)
Massive amount of processes and
documentation does slow down
development, Agile developers claims
that source code is enough
documentation.
243. Cont. Criticism
Criticism of the SDLC that is based on
fiction is that all versions of SDLC are
waterfall-like with no feedback
between steps.
Another false criticism is that a life
cycle approach limits the involvement
of users, yet Agile and Extreme
programming approaches advocate
an analysis-design-code-test
sequence, and that is itself is a cycle.
Editor's Notes
Systems Analysis: the study of a business problem domain for the purpose of recommending improvements and specifying the business requirements for the solution.
Systems Design: the specification or construction of a technical, computer-based solution for the business requirements identified in a systems analysis (often, the design can take the form of a working prototype).
System Design: the process of defining the architecture, components, modules, interfaces and data for a system
SAD includes both of these processes.
SAD is the process of developing and maintaining a system.
Analysis==careful examination (examining) process on sth.
Design==a pattern/drawing or general plan
Knowledge- an understanding gained thru experience. [answers the question: How]
Imagine the string “WifiPassword”. The string / word alone is data. Understanding that it is a string is information. Knowing it is your wifi password is knowledge. And using is to access your wireless is wisdom.
Educational system, computer system
The term system is derived from the Greek word `systema’ which means an organized relationship among functioning units or components.
A system is an orderly group of independent components linked together according to a plan to achieve a common objective.
An organized or established procedure.
Section 3
The system takes input from outside, processes it, and sends the resulting output back to its environment.
Take School System, their cell phone
Integration-It is concerned with how a system is tied together. It means that parts of the system work together within the system even though each part performs a unique function.
Interdependence - It means that part of the organization depends on one another. One subsystem depends upon the input of another subsystem for proper functioning e., output of one subsystem is the required input for the another subsystem.
Purpose==Central objective of the system.
The points at which the system meets its environment are called interfaces; an interface also
occurs between subsystems.
In its functioning, a system must face constraints—the limits (in terms of
capacity, speed, or capabilities) to what it can do and how it can achieve its
purpose within its environment.
Why Decomposition? [ 4 students discussion]
Break a system into small, manageable, and understandable
Subsystems
Focus attention on one area (subsystem) at a time, without
interference from other areas
Concentrate on the part of the system pertinent to a particular group
of users, without confusing users with unnecessary details
Build different parts of the system at independent times and have the
help of different analysts
Reveal the system’s inner workings
Modularity is the direct result of decomposition.
“high cohesion and low coupling” guideline?
Consider Modules as systems or subsystems.
Coupling = communication in between 2 different families...
Cohesion = communication in between father-mother-child within a family.
“high cohesion and low coupling” guideline?
Cohesion vs. coupling?
Cohesion is the indication of the relationship within module. Coupling is the indication of the relationships between modules.
Cohesion shows the module’s relative functional strength. Coupling shows the relative independence among the modules.
Cohesion is a degree (quality) to which a component / module focuses on the single thing. Coupling is a degree to which a component / module is connected to the other modules.
While designing you should strive for high cohesion i.e. a cohesive component/ module focus on a single task (i.e., single-mindedness) with little interaction with other modules of the system. While designing you should strive for low coupling i.e. dependency between modules should be less.
Cohesion: the degree to which the elements of a certain module belong together.
Cohesion is Intra – Module Concept. Coupling is Inter -Module Concept.
Section 5
OO approach combines processes and data; is more natural and modern.
What actions can be done on Info? Storing, processing, disseminating etc….
IS deals with data of the organization
any combination of information technology (IT) and people's activities using that technology to support operations, management, and decision-making
IS refers to the interaction between people, processes, data, and technology.
IS==A SYSTEM THAT PROVIDES THE INFORMATION NEEDED TO ACCOMPLISH THE ORGANIZATION’S TASKS
Hardware – Computers, servers and printers
Software- System softwares and application softwares
Documentation and training materials – The materials created by Systems Analyst to help users to use the software
Specific job roles – The roles associated with the overall system, such as the people who run the computers and the software operating.
Controls- which are the parts of the software written to prevent fraud and theft
People- Who use the software in order to do their job.
Question:
What are system and application softwares?
Iss can be categorized in 4 parts:
TPS, MIS, DSS, ES
TPS automates the handling and capture of data about transactions or business activities ===Data Processing System
TPSs collect, store, modify, and retrieve the transactions of an org.
What is transaction? = an event that generates or modifies data that is eventually stored in an IS.[==Operations]
==Any activity of the organization.
MIS provides info which is needed to manage orgs efficiently and effectively.
Provides managerial information.
DSS supports organizational decision making activities.
eg. Clinical decision support system for medical diagnosis.
Fault diagnosis, medical diagnosis
Project Characteristics:
Temporary- every project has a start and an end.
Unique Deliverable(s)-any project aims to produce some deliverable(s) which can be a product, service, or some another result.
Progressive Elaboration- progress of a project, continuous investigation and improvement become available [ iterative process which begins as a concept]
Deliverable =An end product in a phase of the SDLC.[tangible ‘things’ that the project produces]
Milestones= Dates by which major activities are performed
A project is an activity that:
is temporary having a start and end date
is unique
brings about change
has unknown elements, which therefore create risk
What’s in a project? [ 4 phases]
Propose, Prepare, Produce, Present
Project Mgmt Processes:-
Initiating, Planning, Executing, Closing , Controlling
PM==A controlled process of initiating, planning, executing, and closing down a project.
PM is : the application of knowledge, skills, tools and techniques to project activities to meet project requirements.
Goals should follow SMART rule:
Specific
Measurable
Agreed upon/Attainable
Realistic
Timeframed
Who’s responsible for Project Mgmt.?==Project Manager
Project Team Roles:
Business Analyst=business value
System Analyst=IS issues
Project Manager=budget, time, planning, managing
Infrastructure Analyst= technical issues- how the system will interact with the organization’s hardware, software, networks, databases.
Change management analyst= people and management issues.
Extension
Extension
Initiation==entails generation of the concept behind a new project (project conceptualization); to establish the scope of project [scoping the project], discover its boundaries and specify what project deliverables are expected to be produced.
Initiating: Projects are selected, authorized, and chartered
Planning:
Project Initiation Activities:
Establish project initiation team [organizing an initial core of project team members]
Establish relationship with customer
Establish project initiation plan
Establish management procedures [developing team communication and reporting procedures, job assignments and roles, project change procedures, and determining how project funding and billing will be handled.]
Establish project management environment and workbook
Project workbook
An online or hard-copy repository, for all project correspondence, inputs, outputs, deliverables, procedures, and standards, that is used for performing project audits,
orienting new team members, communicating with management and customers, identifying future projects, and performing postproject reviews.
Project charter
A short, high-level document prepared for both internal and external stakeholders to formally announce the establishment of the project and to briefly describe its objective, key assumptions, and stakeholders.
Elements included in the Charter:
Project title and date of authorization
Project manager name and contact information
Customer name and contact information
Projected start and completion dates
Project description and objectives
Key assumptions or approach
Key stakeholders, roles, responsibilities and signatures
Planning==preparing the Project Mgmt. plan and defining exactly what will happen. [ Scope Planning, Quality Planning, Cost Estimating, HR Planning, Risk Planning]
Planning Phase Activities
Describing project scope, alternatives and feasibility [understand the content and complexity of the project.
During this activity, you should reach agreement on the following questions:
What problem or opportunity does the project address?
What are the quantifiable results to be achieved?
What needs to be done?
Identify and document general alternative solutions for the current business problem or opportunity.
Assess the feasibility of each alternative solution.]
Dividing the project into manageable tasks and logical order
Estimating resources and creating a resources plan [ Use COCOMO;
estimate resource requirements for each project activity
create a project resource plan, which helps assemble and deploy resources in the most effective manner.]
Developing a preliminary schedule
Developing a communication plan [to outline the communication procedures among management, project team members, and the customer]
Determine project standards and procedures [Specify how deliverables are tested and produced]
Identifying and assessing risks [identify sources of project risk and to estimate the consequences of those risks.
Risks might arise from the use of new technology, prospective users’ resistance to change, availability of critical resources, competitive reactions or changes in regulatory actions due to the construction of a system, or team member inexperience with technology or the business area.]
Creating a preliminary budget [outlines the planned expenses and revenues associated with your project.]
Developing a statement of work (for customer)
Setting a baseline project plan [Estimate of project’s tasks and resources]
People are the most important and expensive part of project resource planning.
WBS==The process of dividing the project into manageable tasks and logically ordering them to ensure a smooth evolution between tasks.
Gantt chart==shows time and task(actions/activities)
Developed by Henry Gantt, that illustrates a project schedule
COnstructive COst MOdel (COCOMO)—is an algorithmic software cost estimation model.
Determines whether the information system makes sense for the organization from an economic and operational standpoint.
Planning: Analyze and Plan
Execution=Execute the tasks described in the project plan; Design, Build, Test, Implement
Activities:
Execute Baseline Project Plan
Acquire and assign resources
Train new team members
Keep project on schedule
Ensure quality of project deliverables
Monitor project progress [If the project gets ahead of (or behind) schedule, you may have to adjust
resources, activities, and budgets.]
Adjust resources, budget and/or activities
Manage changes to Baseline Project Plan
Slipped completion dates
Changes in personnel
New activities
Bungled activities [poor/ failed]
Maintain project workbook
Communicate project status
Types of termination
Natural
Requirements have been met[ project completed –success]
Unnatural
Project stopped
Gantt
-Visual Display of project schedule
Limitations:
Doesn’t clearly indicate details regarding the progress of activities.
Doesn’t give a clear indication of interrelation between activities.
PERT
Primary Objective:
-Shortest possible time
-Coping with uncertain activity completion times[ for projects where activity times are generally uncertain]
CPM
Primary Objective:
-plan for the fastest completion of the project [ for projects where activity times are generally known]
Gantt Charts
Useful for depicting simple projects or parts of large projects
Show start and completion dates for individual tasks
PERT Charts
Show order of activities
Critical path scheduling is a scheduling plan where the order and duration of the sequence of activities directly affect the completion date of a project
Critical path is represented by the sequence of connected activities that produces the longest overall time period
It represents the shortest time to complete a project
Slack time refers to the amount of time that an activity can be delayed without delaying the project duration
Advantages of Gantt Charts:
-Time is explicit ( and linear)
-All tasks visible in relationship to others
-deadlines are shown
-project status at intermediate time is shown
PERT Chart shows explicit dependencies between tasks.
CPM(Critical Path Management) Chart is similar to PERT but includes an explicit indication of the “Critical Path”- that sequence of tasks that defines the minimum amount of time for the project.
Gantt Chart uses bar chart while PERT displays the project tasks in a flowchart.
PERT (Program Evaluation and Review Technique) is a network analysis technique that can be used when the individual task time estimates are fairly uncertain. Instead of
assigning a specific value as the duration estimate, PERT uses three time estimates: optimistic, most likely (realistic), and pessimistic. It then combines the three estimates into a single weighted average estimate using the following formula:
Expected completion time (ET) == (O + 4 r + P) /6
The PERT chart is drawn graphically with boxes (called nodes) representing each task and lines (called arcs) showing the dependency between tasks. The time estimates are shown in the nodes.
A Gantt chart is an easy way to schedule tasks. It is a chart on which bars represent each task or
activity. The length of each bar represents the relative length of the task
The main advantage of the Gantt chart is its simplicity.
Another advantage of using a Gantt chart is that the bars representing activities or tasks
are drawn to scale; that is, the size of the bar indicates the relative length of time it will take to
complete each task.
Because Gantt charts do not show how tasks must be ordered (precedence) but simply show when a task should begin and when it should end, they are often more useful for depicting relatively simple projects or subparts of a larger project.
PERT (Program Evaluation Review Technique)
A technique that uses optimistic, pessimistic, and realistic time estimates to calculate the expected time for a particular task.
The optimistic (o) and pessimistic ( p) times reflect the minimum and maximum possible periods of time for an activity to be completed. The realistic time
(r), or most likely time, reflects the project manager’s “best guess” of the amount of time the activity will require for completion.
The activities expressed as bars in the Gantt chart are represented by arrows in the PERT diagram. The length of the arrows
has no direct relationship with the activity durations. Circles on the PERT diagram are called
events and can be identified by numbers, letters, or any other arbitrary form of designation. The
circular nodes are present to
(1) recognize that an activity is completed and
(2) indicate which activities need to be completed before a new activity may be undertaken (precedence).
In reality activity C may not be started until activity A is completed. Precedence is not indicated at all in the Gantt chart, so it is not possible to tell whether activity C is scheduled to start on day 4 on purpose or by coincidence.
A project has a beginning, a middle, and an end; the beginning is event 10 and the end is event 50. To find the length of the project, each path from beginning to end is identified, and the length of each path is calculated.
In this example path 10–20–40–50 has a length of 15 days, whereas path 10–30–40–50 has a length of 11 days. Even though one person may be working on path
10–20–40–50 and another on path 10–30–40–50, the project is not a race. The project requires that both sets of activities (or paths) be completed; consequently, the project takes 15 days to complete.
The longest path is referred to as the critical path. Although the critical path [The shortest time in which a project can be completed] is determined by calculating the longest path, it is defined as the path that will cause the whole project to fall behind if even one day’s delay is encountered on it. Note that if you are delayed one day on path 10–20–40–50, the entire project will take longer, but if you are delayed one day on path 10–30–40–50, the entire project will not suffer. The leeway to fall behind somewhat on noncritical paths is called slack time [Slack time =The amount of time that an activity can be delayed without delaying the project]
SDLC phases:
1-Project identification and selection
2-Project initiation and planning
3-Analysis
4-Design
4.1 Logical design
4.2 Physical design
5-Implementation
6-Maintenance
A systems development lifecycle (SDLC) has three primary objectives:
ensure that high quality systems are delivered,
provide strong management controls over the projects, and
maximize the productivity of the systems staff.
SDLC--- as a standard for benchmarking progress on a project; a sequence of activities;
It consists of a set of steps or phases to be followed sequentially to develop a system.
The system development life cycle is the overall process of developing, implementing, and retiring information systems through a multistep process from initiation, analysis, design, implementation, and maintenance to disposal.
SDLC=Standard process followed in an organization to conduct all the steps necessary to analyze, design, implement and maintain IS.
===Series of steps used to manage the phases of development for an information system or
The traditional methodology used to develop, maintain, and replace IS.
Phases in SDLC:
Planning
Analysis
Design
Implementation
Maintenance
2 Testing should occur through out the life cycle, as each unit is completed, as well as at completion of coding & installation. Planning for testing & installation should occur during the Planning & Selection phase.
The Terms of Reference
Project goal
Scope
Constraints
Two Primary Activities in this phase:
1. Identify the need for a new or enhanced system. Information needs of the organization are examined, and projects to meet these needs are identified. A feasibility study is conducted.
2. Investigate the system and determine the proposed system’s scope
Project identification and selection
Project identification and selection consists of three primary activities:
Identifying potential development projects, classifying and ranking projects [Assessing the merit of
potential projects], and selecting projects for development.
Possible Evaluation Criteria when classifying and ranking projects
Value chain analysis== Extent to which activities add value and costs when developing products and/or services; information systems projects providing the greatest overall benefits will be given priority over those with fewer benefits
Strategic alignment== Extent to which the project is viewed as helping the organization achieve its strategic objectives and long-term goals
Potential benefits== Extent to which the project is viewed as improving profits, customer service, etc., and the duration of these benefits
Resource availability== Amount and type of resources the project requires and their availability
Project size/duration==Number of individuals and the length of time needed to complete the project
Technical difficulty/risks ==Level of technical difficulty to complete the project successfully within given time and resource constraints
Factors needed to be considered during Selecting a Project:
Perceived needs of the organization;
Existing systems and ongoing projects;
Resource availability;
Evaluation criteria;
Current business conditions;
Perspectives of the decision makers.
Decision Outcome
• Accept Project • Reject Project • Delay Project • Refocus Project • End-User Development • Purchase System • Modify and Resubmit
steering committee [approval committee]==a committee that decides on the priorities or order of business of an organization and manages the general course of its operations.
===============An advisory committee usually made up of high level stakeholders and/or experts who provide guidance on key issues such as company policy and objectives, budgetary control, marketing strategy, resource allocation, and decisions involving large expenditures.
Prototyping
Designing and building a scaled-down but working version of a desired system is known as prototyping.
Computer-aided software engineering (CASE)
Software tools that provide automated support for some portion of the systems development process.
The criteria commonly used to evaluate projects are
Value chain analysis: Extent to which activities add greatest benefits
Strategic alignment: Extent the projects achieves the long term goals
Potential benefits: Extent to which the project helps to improve profits, Customer service, etc. and the duration of the benefits
Resource availability: Amount and type of resources required for the project
Project size / duration: Number of individuals and duration to complete
Technical difficulty / risk: Level of technical difficult to complete.
BPP(Baseline Project Plan)
an internal document used by the development team but not shared with customers
contains all information collected and analyzed during the project initiation and planning activity
reflects the best estimate of the project’s scope, benefits, costs, risks and resource requirements
The SOW (Statement of Work)
a short document prepared for the customers that describes what the project will deliver and outlines all work required to complete the project
a useful communication tool that assures that both system analysts and customers have a common understanding of the project.
defines the scope and the working agreements between two parties, typically between a client and a service provider. Therefore, SOW carries a legal gravity as well.
The main purpose of a SOW is to define the liabilities, responsibilities and work agreements between clients and service providers.
Introduction—brief overview of the entire document==executive summary.
System Description=
Format of SOW:
Scope, Location, Timelines ( Development time, Warranty time and Maintenance time), Delivery Schedule, Standards, Acceptance Criteria ( minimum criteria to accept a delivery), Mode of contract and Payments (fixed bid, retainer)
In fixed bid, the project cost is a constant and it is up to the service provider to optimize the resource allocation in order to maintain the profit margins.
The client does not worry about the number of resources, as long as the delivery schedule is met. In the retainer model, the client pays for the number of resources allocated to the project.
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A feasibility study aims to objectively and rationally uncover the strengths and weaknesses of an existing business or proposed venture, opportunities and threats present in the environment, the resources required to carry through, and ultimately the prospects for success.
The acronym TELOS refers to the five areas of feasibility - Technical, Economic, Legal, Operational and Scheduling.
A feasibility study is a test of a system proposal according to its workability, impact on the organization, ability to meet user needs, arid effect we use of resources.
It focuses on three major questions:
What are the-user’s demonstrable- needs and how does a candidate system meet them?
What resources are available for given candidate systems?
Is the problem worth solving?
What is the likely impact of the candidate system on the organization?
How well does it fit within the organization?
Technical feasibility – lays out details on how a good or service will be delivered, which includes transportation, business location, technology needed, materials and labor.
Whether the technology needed for the system exists; how difficult it will be to build; whether the firm has enough experience using that technology.
Answers: Can We BUILD It?
Is the technology needed for the proposed system available; has it been proven (e.g. well used by other organizations) and is there adequate support available for it?
Is it possible to integrate the technology with the existing technical infrastructure in the organization and is the necessary technical equipment available?
Does the IT team have the expertise necessary to develop, build and maintain using the technology?
the availability of technical resources and expertise.
Financial Feasibility: Projects how much start-up capital is needed, sources of capital, returns on investment, etc.
quantification and identification of all the benefits expected
==a projection of the amount of funding or startup capital needed, what sources of capital can and will be used, and what kind of return can be expected on the investment.
Can the firm afford to build the system; whether its benefits should substantially exceed its costs; whether the project has higher priority than other projects.
Economic feasibility means that the projected benefits of the proposed system outweigh the estimated costs usually considered the total cost of ownership (TCO),
which includes ongoing support and maintenance costs, as well as acquisition costs.
To determine TCO, the analyst must estimate costs in each of the following areas:
• People, including IT staff and users
• Hardware and equipment
• Software, including in-house development as well as purchases from vendors
• Formal and informal training
• Licenses and fees
• Consulting expenses
• Facility costs
• The estimated cost of not developing the system or postponing the project
Answers: Will It Provide Business Value?
It includes study concerning contracts, liability, violations, and legal other traps frequently unknown to the technical staff.
copyright laws and financial reporting standards.
copyright or nondisclosure issues, data capture or transferring,
concerned with issues like whether the system will be used if it is developed and implemented;
Whether there will be resistance from users that will effect the possible application benefits?;
Does management support the project?
Will the new system fit in with existing operations/systems?
Will peoples’ jobs need to change or will they need retraining in order to use the new system?
Are the members of staff happy to use the new system?
Will it be accepted by the org?
How much time is available to build the new system; when it can be built; interference with normal business operatioins.
Are the deadlines for the project reasonable/achievable?
Organizational Feasibility: If we build it, will it be used?
Analysis—a thorough study and investigation
The two parts to analysis are determining requirements and structuring requirements.
Thoroughly studying the organization’s current procedures and the information systems used to perform tasks such as general ledger, shipping, order entry, machine scheduling, and payroll.
Structuring means taking the system requirements you find during requirements determination and ordering them into tables, diagrams, and other formats that make them easier to translate into technical system specifications.
Sub-phases:
determine what the users want from a proposed system [Determine the requirements of the system--involves a careful study of any current systems, manual and computerized ]
study the requirements and structure them according to their interrelationships, eliminating any redundancies.
A ledger is a book in which a company or organization writes down the amounts of money it spends and receives.
As-is system==current system
To-be system==new system
The purpose of the Analysis phase is as follows:
To determine how the current information system in the organization functions
To assess what users would like to see in the new system i.e. gather requirements
To structure the requirements so that they can be translated into technical system specifications
The characteristics of a good systems analyst in determining the requirements are:
Impertinence= You should question everything; You should question about each and every aspects involved in the system. [question everything]
Impartiality == be fair and open-minded [Consider issues raised by all parties]
Relaxing of constraints==think outta the box/ don’t restrain your constraints.
Attention to details==Thin every thing , every condition and every facts during Req't determination. [consider every fact] [[every fact must fit]
Reframing==challenge yourself to new ways. [look at the org and the problem in new ways]
Requirement— necessary attribute , capability, characteristic, or quality of a system for it to have value and utility to a customer or org or other stakeholder.
A requirement is a singular documented physical and functional need that a particular design, product or process must be able to perform.
A requirement is simply a statement of what the system must do or what characteristics it needs to have.
During Gathering requirements, the system analyst should be:
Impertinent, impartial, relaxing of constraints, attention to details, reframing
The final deliverable of the analysis phase is the system proposal, which compiles the detailed requirements definition statement, use cases, process models, and
data model together with a revised feasibility analysis and work plan.
At the conclusion of the analysis phase, the system proposal is presented to the approval committee, usually in the form of a system walk-through. The goal of the walk-through is to explain the system in moderate detail so that the users, managers, and key decision makers clearly understand it,
can identify any needed modifications, and
are able to make a decision about whether the project should continue.
The Proposal is also known as a Statement of Requirements, Statement of Work or Baseline Project Plan.
The Proposal is a document that is prepared by the project team and is presented to the customer i.e. the owner of the new system. It promotes a common understanding of what the project aims to do, between the project team and the customer. It must be presented in a format that clearly shows the advantages of the project to the organization and its users. It can be long and detailed or it may be short and to the point – this depends on the size of the project and whether it is being presented to internal or external customers.
contemporary
7 steps to conduct interview:
1. Determine the people to interview. [select the right person to interview and ask’em the right questions. Group interview + individual interview (one on one)]
2. Establish objectives for the interview.
3. Develop interview questions.[Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents(departures); The interview should consist of several different kinds of questions: open-ended, closed-ended, or questions with a range of responses.]
4. Prepare for the interview.[schedule interview, suggest a specific day and time and let the interviewee know how long you expect the meeting to last. Remind the interviewee by email or call before appointment. Keep department managers [any concerned bodies] informed of your meeting with their staff members.
Send a list of topics to an interviewee several days before the meeting so the person can prepare for the interview adjust location of interview.]
5. Conduct the interview.[begin by introducing yourself, describing the project, and explaining your interview objectives. Ask questions in the order in which you prepared'em and give the interviewee sufficient time to provide thoughtful answers. After asking a question, allow the person enough time to think about the question and arrive at an answer.
You must concentrate on what is said and notice any nonverbal communication that takes place. This process is called engaged listening. Thank the person.]
6. Document the interview.[note taking should be kept to a minimum, during interview. After interview, record the info quickly. Tape recorders are effective but inform the interviewee before using it. Even for sensitive questions, if the interviewee wants not to be recorded, explain that you'll turn off the tape for a period of time during the interview. Send a memo to the interviewee expressing your appreciation for his/her time and cooperation.
7. Evaluate the interview.
5 Basic Steps
Selecting Interviewees
Design interview questions
Prepare for interview
Conduct the interview
Post-interview follow-up
Open-ended questions encourage spontaneous and unstructured responses. Such questions are useful when you want to understand a larger process or draw out the interviewee’s opinions, attitudes, or suggestions.
Questions in interviews and on questionnaires that have no prespecified answers.
Here are some examples of open-ended questions: What are users saying about the new system? How is this task performed? Why do you perform the task that way? How
are the checks reconciled? What added features would you like to have in the new billing system?
Also, you can use an open-ended question to probe further by asking: Is there anything else you can tell me about this topic?
Closed-ended questions limit or restrict the response. You use closed-ended questions when you want information that is more specific or when you need to verify facts.
Closed-ended questions : Questions in interviews and on questionnaires that ask those responding to choose from among a set of specified responses.
Examples of closed-ended questions include the following: How many personal computers do you have in this department? Do you review the reports before they are sent out? How many hours of training does a clerk receive? Is the calculation procedure described in the manual? How many customers ordered products from the Web site last month?
RANGE-OF-RESPONSE QUESTIONS are closed-ended questions that ask the person to evaluate something by providing limited answers to specific responses or on a numeric scale. This method makes it easier to tabulate the answers and interpret the results. Range-of-response questions might include
these: On a scale of 1 to 10, with 1 the lowest and 10 the highest, how effective was your training? How would you rate the severity of the problem: low, medium,
or high? Is the system shutdown something that occurs never, sometimes, often,usually, or always?
Open-ended questions--are usually used to probe for information when you cannot anticipate all possible responses or when you do not know the precise question to ask.
advantage of open-ended questions
previously unknown information can surface.
Putting the interviewee at ease
Allowing the interviewer to pick up on the interviewee's vocabulary, which reflect his or her education, values, attitudes, and beliefs.
Providing richness of detail
Revealing avenues of further questioning that may have gone untapped.
Making it more interesting for the interviewee
allowing more spontaneity
Disadvantage:
Length of time it can take for the questions to be answered.
Asking questions that may result in too much irrelevant detail.
Possibly losing control of the interview.
Allowing responses that may take too much time for the amount of useful information gained.
Potentially seeming that the interviewer is unprepared.
Possibly giving the impression that the interviewer is on a “fishing expedition” with no real objective for the interview.
Advantage:
Do not necessarily require a large time commitment—more topics can be covered.
Saving time.
Easily comparing interviews.
Getting to the point quickly.
Keeping control over the interview.
Covering lots of ground quickly.
Getting to relevant data.
Disadvantage:
Being boring for the interviewee.
Failing to obtain rich detail (because the interviewer supplies the frame of reference for the interviewee).
Missing main ideas for the preceding reason.
Failing to build rapport between interviewer and interviewee.
useful information that does not quite fit the defined answers may be overlooked as the respondent tries to make a choice instead of providing his or her best answer.
A special kind of closed question is the bipolar question. This type of question limits the interviewee even further by only allowing a choice on either pole, such as yes or no, true or false, agree or disagree.
The strongest probe is the simplest: the question, “Why?”
Other probes are “Can you give me an example of a time you did not find the system trustworthy?” and “Will you elaborate on that for me?”
The purpose of the probe is to go beyond the initial answer to get more meaning, to clarify, and to draw out and expand on the interviewee’s point.
Probes may be either open-ended or closed questions.
It is essential to probe. Most beginning interviewers are reticent about probing and consequently accept superficial answers.
Probing questions follow up on what has just been discussed in order for the interviewer to learn more, and they often are used when the interviewer is unclear about an interviewee’s answer. They encourage the interviewee to expand on or to confirm information from a previous response, and they are a signal that the interviewer is listening and interested in the topic under discussion.
Eg.
Why?
• Can you give me an example?
• Can you explain that in a bit more detail?
. What makes you feel that way?
Tell me step by step what happens after a customer clicks the “Submit” button on the Web registration form.
Ideas to keep in mind when designing Questionnaires:
• Keep the questionnaire brief and user-friendly.
• Provide clear instructions that will answer all anticipated questions.
• Arrange the questions in a logical order, going from simple to more complex topics.
• Phrase questions to avoid misunderstandings; use simple terms and wording.
• Try not to lead the response or use questions that give clues to expected answers.
• Limit the use of open-ended questions that are difficult to tabulate.
• Limit the use of questions that can raise concerns about job security or other
negative issues.
• Include a section at the end of the questionnaire for general comments.
• Test the questionnaire whenever possible on a small test group before finalizing it
and distributing to a large group.
Good Questionnaire Design
• Begin with nonthreatening and interesting questions.
• Group items into logically coherent sections.
• Do not put important items at the very end of the questionnaire.
• Do not crowd a page with too many items.
• Avoid abbreviations.
• Avoid biased or suggestive items or terms.
• Number questions to avoid confusion.
• Pretest the questionnaire to identify
When you seek input from a large group, a questionnaire is a very useful tool. On the other hand, if you require detailed information from only a few people, then you probably should interview each person individually.
Is it better to interview or use a questionnaire? Each situation is different, and you must consider the type of information, time constraints, and expense factors.
Hawthorne effect [Observer Effect] —the alteration of behavior by the subjects of a study due to their awareness of being observed.
A type of reactivity in which individuals modify or improve an aspect of their behavior in response to their awareness of being observed.
an increase in worker productivity produced by the psychological stimulus of being singled out and made to feel important.
The stimulation to output or accomplishment that results from the mere fact of being under observation
Remember how you drove the last time a police car followed you?
Remember how you act before your loved ones?
DO:
Watching users do their jobs; to obtain firsthand info; can cause people to change their normal operating behavior.
The advantages of observation over asking questions is that the analyst can see what the user’s behavior and interactions with the system actually are, not what they say they are.
There are also disadvantages to observation – while being observed, people may not behave normally ( if they know they are being observed) – they may change their behavior. Also the time at which the observation takes place may mean that the analyst sees only a small subset of the work done by the user.
Documents like: paper reports including performance reports, memorandums, policy manuals, user training manuals, organization charts, and forms, problem reports filed by the system users etc. can be analyzed as they can be rich source of information about issues with the existing system.
Documents: forms, reports, policy manuals, organizational charts.
Different Approaches to Improving Development [Application Development Methodologies]
Prototyping
CASE Tools
JAD
RAD
Agile Methodologies
eXtreme Programming
approaches that streamline and improve the systems analysis and design process from different perspectives:
Prototyping, CASE, JAD, RAD, PD, Agile
Advantages of Prototyping
the potential for changing the system early in its development,
the opportunity to stop development on a system that is not working, and
the possibility of developing a system that more closely addresses users’ needs and expectations
Prototyping tests system concepts and provides an opportunity to examine input, output, and user interfaces before final decisions are made.
A prototype can serve as an initial model that is used as a benchmark to evaluate the finished system, or the prototype itself can develop into the final version
Prototyping Vs. Modeling
Modeling produces a graphical representation of a concept or process, whereas
prototyping involves the creation of an early working model of the information or its components.
The key advantages of the prototyping technique are:
(1) it involves the user in analysis and design, and
(2) it captures requirements in concrete, rather than verbal or abstract, form.
A prototype can be developed with a CASE tool, a software product that automates steps in the SDLC.
The analyst works with users to determine the initial or basic requirements for the system. The analyst then quickly builds a prototype. When the prototype is completed, the users work with it and tell the analyst what they like and do not like about it. The analyst uses this feedback to improve the prototype and takes the new version back to the users. This iterative process continues until the users are relatively satisfied with what they have seen.
Users can easily visualize the system from the very beginning.
Prototypes are useful in seeking user reactions, suggestions, innovations, and revision plans
Software prototyping is the activity of creating prototypes of software applications, i.e., incomplete versions of the software program being developed. It is an activity that can occur in software development and is comparable to prototyping as known from other fields, such as mechanical engineering or manufacturing.
A prototype typically simulates only a few aspects of, and may be completely different from, the final product.
Prototyping has several benefits: The software designer and implementer can get valuable feedback from the users early in the project. The client and the contractor can compare if the software made matches the software specification, according to which the software program is built. It also allows the software engineer some insight into the accuracy of initial project estimates and whether the deadlines and milestones proposed can be successfully met.
The JAD approach, in comparison with the more traditional practice, is thought to lead to faster development times and greater client satisfaction, because the client is involved throughout the development process.
The focus on a limited prototype can distract developers from properly analyzing the complete project. since a prototype is limited in functionality it may not scale well if the prototype is used as the basis of a final deliverable, which may not be noticed if developers are too focused on building a prototype as a model.
Users can begin to think that a prototype, intended to be thrown away, is actually a final system that merely needs to be finished or polished. Users may expect the prototype to accurately model the performance of the final system when this is not the intent of the developers.
Objectives:
increasing productivity and improving the overall quality of systems.
The general types of CASE tools include:
Diagramming tools that enable system process, data, and control structures to be represented graphically.
Computer display and report generators that help prototype how systems “look and feel” to users. Display (or form) and report generators also make it easier for the systems analyst to identify data requirements and relationships.
Analysis tools that automatically check for incomplete, inconsistent, or incorrect specifications in diagrams, forms, and reports.
A central repository that enables the integrated storage of specifications, diagrams, reports, and project management information.
Documentation generators that help produce both technical and user documentation in standard formats.
Code generators that enable the automatic generation of program and database definition code directly from the design documents, diagrams, forms, and reports.
Repository==An integrated and standard database
Advantage:
to increase productivity,
communicate more effectively with users, and
integrate the work that they do on the system from the beginning to the end of the life cycle.
Visible Analyst (VA) is one example of a CASE tool that enables systems analysts to do graphical planning, analysis, and design in order to build complex client/server applications and databases. Visible Analyst and another software product called Microsoft Visio allow users to draw and modify diagrams easily.
CASE is a technique that uses powerful software, called CASE tools, to help systems analysts develop and maintain information systems. CASE tools provide
an overall framework for systems development and support a wide variety of design methodologies, including structured analysis and object-oriented
analysis.
Because CASE tools make it easier to build an information system, they boost IT productivity and improve the quality of the finished product
Computer-aided software engineering (CASE) is a category of software that automates all or part of the development process.
Some CASE software packages are primarily used during the analysis phase to create integrated diagrams of the system
and to store information regarding the system components (often called upper CASE), whereas others are design-phase tools that create the diagrams and then generate
code for database tables and system functionality (often called lower CASE).
CASE tools: Advantages
Help standardization of notations and diagrams
Help communication between development team members
Automatically check the quality of the A&D models
Reduction of time and effort
Enhance reuse of models or models’ components
CASE tools: Disadvantages
Limitations in flexibility of documentation
May lead to restriction to the tool’s capabilities
Major danger: completeness and syntactic correctness does NOT mean compliance with requirements
Costs associated with the use of the tool: purchase + training
There are various CASE applications available to help with all stages of the SDLC.
They should not be considered a silver bullet for project development but are supporting tools
CASE tools: Automated Diagram Support
Checks for syntactic correctness
Data dictionary support
Checks for consistency and completeness
Navigation to linked diagrams
Layering
Requirements traceability
Automatic report generation
System simulation
Performance analysis
By gathering the people directly affected by an IS in one room at the same time to work together to agree on system requirements and design details, time and organizational resources are better managed.
The primary purpose of using JAD in the analysis phase is to collect systems requirements simultaneously from the key people involved with the system.
Is conducted off-site.
JAD is a popular fact-finding technique that brings users into the development process as active participants.
JAD focuses on team-based fact-finding
Both JAD and RAD use teams composed of users, managers, and IT staff. The difference is that JAD focuses on team-based fact-finding, which is only one phase of
the development process, whereas RAD is more like a compressed version of the entire process.
Team-based techniques: JAD, RAD, Agile
The IT department’s goal is to deliver the best possible information system, at the lowest
possible cost, in the shortest possible time.
joint application development (JAD) is a user-oriented technique for fact-finding and requirements modeling.
JAD is more expensive
JAD is a methodology that involves the client or end user in the design and development of an application through a succession of collaborative workshops known as JAD sessions.
JAD centers more on people than on technology; while RAD focuses more on development
JAD encourages a partnership between business clients, management and IS personnel.
The JAD approach, in comparison with the more traditional practice, is thought to lead to faster development times and greater client satisfaction, because the client is involved throughout the development process.
Users feel a sense of ownership in the results, and support for the new system.
While the end product of JAD is a requirement model, the end product of RAD is the new information system.
Advantages and Disadvantages of JAD
JAD is more expensive and can be cumbersome if the group is too large relative to the size of the project.
professionals' valuable time can be easily wasted. If JAD session organizers do not study the elements of the system being evaluated, an incorrect problem could be addressed, incorrect people could be invited to participate, and inadequate problem-solving resources could be used.
JAD Session Leader [==Facilitator] =Develops an agenda, acts as a facilitator, and leads the JAD session
JAD is said to lead to increased quality, reduced costs, and life cycle time reduction.
Joint application development (JAD) is a popular fact-finding technique that brings users into the development process as active participants.
JAD sessions, whether for Joint Application Design or Joint Application Development, have many other names, include: Accelerated Design, Facilitated Meetings, Facilitated Sessions, Facilitated Team Techniques, Facilitated Work Sessions, Group Design, Interactive Design, Interactive JAD, Joint Sessions and User Centered Design. Walter Moeller, a senior consultant with Principle Partners, Inc., calls it Facilitated Information Gathering Session.
Benefits:
1.Reduced dev’t time: information can be obtained and validated in a shorter time frame by involving all participants
2.Improved system quality and productivity: quality requirement gathering
3. Reduced system cost: Reduced development time reduces the labor cost for developers, as well as users.
4. Enhanced communication and relationship between business end-users and IT personnel
5. Cultivate ownership, easier acceptance (buy-in) and stronger commitment by users
6. Enhanced education for participants and observers
The scribe[Recorder] records and documents all the sessions. The scribe is to seek clarity in meaning and is allowed to ask questions but not in any way influence discussions.
Sponsor:-This is usually a high-level manager or executive, who charters the project. The sponsor makes the final decisions and finances the project. Commitment of the sponsor to the project is of utmost importance not only because of his role but also as a motivating force for the rest of the team.
RAD involves gaining user acceptance of the interface and developing key system capabilities as quickly as possible.
RAD sacrifices computer efficiency for gains in human efficiency in rapidly building and rebuilding working systems
RAD methodologies can overlook important systems development principles, which may result in problems with systems developed this way.
RAD grew out of the convergence of two trends: the increased speed and turbulence of doing business in the late 1980s and early 1990s, and the ready
availability of high-powered computer-based tools to support systems development and easy maintenance. As the conditions of doing business in a changing,
competitive global environment became more turbulent, management in many organizations began to question whether it made sense to wait two to three
years to develop systems that would be obsolete upon completion.
On the other hand, CASE tools and prototyping software were diffusing throughout organizations, making it relatively easy for end users to see what their systems would
look like before they were completed. Why not use these tools to address the problems of developing systems more productively in a rapidly changing business
environment? So RAD was born.
Planning and design phases in RAD are shortened by focusing work on system functional and user interface requirements at the expense of detailed business analysis and concern for system performance issues.
Notice that RAD involves users in each part of the development effort, with intense participation in the business part of the design.
RAD provides a fast-track approach to a full spectrum of system development tasks, including planning, design, construction, and implementation.
The primary advantage is that systems can be developed more quickly with significant cost savings.
RAD resembles a condensed version of the entire SDLC, with users involved every step of the way.
RAD==a team-based technique that speeds up information systems development and produces a functioning information system.
Like JAD, RAD uses a group approach, but goes much further. While the end product of JAD is a requirements model, the end product of RAD is the new IS.
RAD is a complete methodology, with a four-phase life cycle that parallels the traditional SDLC phases. Companies use RAD to reduce cost and development time,
and increase the probability of success.
There are pressing reasons for speeding up application development.
RAD cycle is limited to the design, construction, and development phases
System analyst: the organizational role most responsible for the analysis and design of IS.
The systems analyst is a key person analyzing the business, identifying opportunities for improvement, and designing information systems to implement these ideas.
Prototyping, CASE, and JAD are key tools that support RAD.
The fundamental principle of any RAD methodology is to delay producing detailed system design documents until after user requirements are clear.
Rapid Application Development is defined as a methodology created to radically decrease the time needed to design and implement information systems by relying on extensive user involvement, JAD sessions, prototyping, integrated CASE tools, and code generators (in particular, object-oriented programming).
RAD is based on the concept that systems can be developed faster and of higher quality by gathering requirements through workshops or focus groups, prototyping and early, reiterative user testing of designs, use of already existing software components and less formality in reviews and other team communication .
The key objectives of RAD are: High Speed, High Quality and Low Cost.
Participatory Design emphasizes democracy in the workplace and user involvement in all stages of the design process
Joint Application Design (JAD) is a group process involving users and systems development staff in which all parties discuss the needs for an information system and reach a shared understanding. Participatory Design (PD) is a systems development approach that originated in northern Europe in which users and the improvement in their work lives is the central focus
They also differ in their goals - JAD is intended to accelerate the design of information systems and promote comprehensive, high-quality results, while PD seeks to accentuate the social context of the workplace and promote workers' control over their work and their lives.
The rationale behind JAD and PD: the more users are involved in systems development the more successful the resulting system will be. [truism]
Participatory Design (PO) - widely termed the -Scandinavian model- of systems development - advocates a much stronger form of user involvement than that of JAD, in which workers participate in designing computer systems they will employ.
In PD, there is power shift to Users in controlling system development project.
Business Process Re-engineering
Breakthrough=advance/ revolution/ innovative
Re-engineering, reinventing, improving, enhancing, renewing a certain established routine procedure or business process [called Legacy System] into a better updated ones.
Data Modeling Vs Process Modeling
Data modeling is the process of creating a conceptual model of data objects and how the data objects associate with each other in a database. Data modeling focuses on how the data objects are organized than on the operations that are performed on data. Process modeling or specifically Business Process Modeling (BPM) involves representing processes of an enterprise such that the existing processes could be analyzed to improve quality and efficiency. BMP is generally a diagrammatic representation of the sequence of activities carried out in an organization. It displays the events, actions and connection points from start to the end of the sequence.
There are two main methods used for data modeling called the Entity-Relationship (ER) approach and the Object Model. Most widely used among these two is the ER model.
A conceptual data model identifies the highest-level relationships between the different entities. Features of conceptual data model include:
Includes the important entities and the relationships among them.
No attribute is specified.
No primary key is specified
A logical data model describes the data in as much detail as possible, without regard to how they will be physical implemented in the database. Features of a logical data model include:
Includes all entities and relationships among them.
All attributes for each entity are specified.
The primary key for each entity is specified.
Foreign keys (keys identifying the relationship between different entities) are specified.
Normalization occurs at this level.
Entity-Relationship diagram (widely known as ER diagram), which is a pictorial representation of data objects and interactions between them.
Data model represents the data objects and the interactions among the data objects in an organization, while the process model is a diagrammatic representation of a sequence of activities in an organization. The data model could be seen as a part of the business process model, which specifies how the information in the organization should be stored effectively to improve the overall performance. In a typical organization there are important interactions between the data model and the business process model.
Logic models are a depiction of the logical relationships between the resources, activities, outputs and outcomes of a program
The primary role of a systems analyst is to study the problems and needs of an organization in order to determine how people, methods, and information
technology can best be combined to bring about improvements in the organization.
Sometimes called Req’t Analyst.
SA is responsible for ensuring that the requirements set forth by the businesss
are captured and documented correctly before the solution is developed and implemented.
Four SA Skills:
Analytical skills [enable you to understand the organization and its functions, to identify opportunities and problems, and to analyze and solve problems.],
Technical skills [help you understand the potential and the limitations of information technology],
Management skills [help you manage projects, resources, risk, and change]
Interpersonal skills [help you work with end users as well as with other analysts and programmers]
Logical Design: all functional features of the system chosen for development in analysis are described independently of any computer platform.
Physical Design: the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished.
Logical system description:
Description of a system that focuses on the system function and purpose without regard to how the system will physically implemented
Physical system description:
Description of a system that focuses on the how the system will be materially constructed.
The purpose of the analysis phase is to figure out what the business needs. The purpose of the design phase is to decide how to build it. System design is the determination
of the overall system architecture—consisting of a set of physical processing components, hardware, software, people, and the communication among them—that will satisfy the system’s essential requirements.
develop a custom application in-house [Custom development, building a new system from scratch;
buy a packaged system and (possibly) customize it […. because it makes little sense to reinvent the wheel…].and
rely on an external vendor, developer, or service provider to build or provide the system
Architecture design= the plan for how the IS components will be distributed across multiple computers and what hardware, OS software, and application software will be used on each computer(e.g., Windows or Linux operating system software).
Major architectural components of any system: Software and Hardware.
User interface is the part of the system with which the users interact. It includes the screen displays that provide navigation through the system, the screens and forms
that capture data, and the reports that the system produces (whether on paper, on the Web, or via some other media).
"Input design is the process of converting user originated inputs to computer based formats“
During design of input, the analyst should decide on the following details:
What data to input
What medium to use
How data should be arranged
How data should be coded i.e. data representation conventions
The dialogue to guide users in providing input i.e. informative messages that should be provided when the user is entering data. Like saying, "It is required. Don't leave it blank."
Data items and transactions needing validation to detect errors
Methods for performing input validation and steps to follow when errors occur
Output refers to the results and information that are generated by the system. In many cases, output is the main reason for developing the system and the basis on which the usefulness of the system is evaluated.
While designing the output of system, the following factors should be considered:
Determine what information to present
Decide on the mode of output, i.e. whether to display, print, or "speak" the information and select the output medium
Arrange the presentation of information in an acceptable format
Decide how to distribute the output to intended recipients
Outputs are data going out from the system to the users. The users may be an external entity, or maybe internal (boundary between computer-system and manual system).
Outputs present information to system users. Outputs, the most visible component of a working information system, are the justification for the system. During systems analysis, you defined output needs and requirements, but you didn't design those outputs. In this section, you will learn how to design effective outputs for system users.
Outputs present information to system users. Outputs, the most visible component of a working information system, are the justification for the system. During systems analysis, you defined output needs and requirements, but you didn't design those outputs. In this section, you will learn how to design effective outputs for system users
Figure 13.1 Typical External Output
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Figure 13.2 Typical External Turnaround Output
Notice that the invoice has a top and lower portion. The top portion is to be detached and returned with the customer payment.
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Figure 13.3a Sample Detailed Report
An example detailed report is depicted in the figure above. This example is a listing of all purchase orders that were generated on a particular date. Other example detail reports would be a detailed listing of all customer accounts, orders, or products in inventory.
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Figure 13.3b Sample Summary Report
A sample summary report is depicted in the figure above. This report summarizes the month and year’s total sales by product type and category.
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Figure 13.3c Sample Exception Report
An example is depicted in the figure above where delinquent member accounts are identified for following-up. Another classic examples of an exception report is a report that identifies items that are low in stock (soon to run out).
Examples of exception reports are a listing of all employees with no absences for the year, a listing of all salespeople who did not meet their monthly sales quota, or a report on consumer complaints made in the last six months.
Exception reports make the decision maker aware of deviations from satisfactory values.
An exception report displays only those records that meet a specific condition or conditions.
For example, a credit manager might use an exception report to identify only those customers with past due accounts, or a customer service manager might want a report on all packages that were not delivered within a specified time period
We assume you are familiar with different output devices, such as printers, plotters, computer output on microfilm (COM), and CRT display terminals. These are standard topics in most introductory information systems courses. In this chapter, we are more concerned with the actual output than with the device.
Detail Reports: Lists detailed information about all the items requested [When user needs full information about the items]
Summary Reports: Lists summary information about all items [When user needs brief information on many items].
Turnaround document: Outputs that “turn around” and become inputs[When a user (often a customer) needs to return an output to be processed. Turnaround documents are a special type of report that are both outputs and inputs.
Graphs: Charts used in addition to and instead of tables of numbers [When users need to compare data among several items.
Types of Output
Whether the output is a formatted report or a simple listing of the contents of a file, a computer process will produce the output.
System output may be :
1. A report
2. A document
3. A message
Reports
Detail reports, summary reports, exception reports, turnaround documents, graphs
Media
Paper
more traditional medium, relatively permanent, easy to use; highly portable; Inflexible [once report is printed, can't be reformatted]; expensive, hard to duplicate
Electronic[screen, microfilm, video/audio, CDROM,DVD]
stored in electronic format on file servers or Web Servers; minimum cost
Most of the computer programs written probably generated tabular reports.
Zoned output is often used in conjunction with tabular output. For example, an order output contains zones for customer and order data in addition to tables (or rows of columns) for ordered items.
Logical Design : It reviews the present physical system, i.e., prepares input and output specifications; makes edit, security, control specifications; details the implementation plan; and prepares a logicil design walkthrough.
Physical Design : It maps out the details of the physical system, plans the system implementation, devises a test and implementation Ian, and specifies any new hardware and software.
The logical design is more conceptual and abstract than the physical design. In the logical design, you look at the logical relationships among the objects. In the physical design, you look at the most effective way of storing and retrieving the objects.
In a sense, logical design is what you draw with a pencil before building your warehouse and physical design is when you create the database with SQL statements.
a systematic approach of decomposing tables to eliminate data redundancy and undesirable characteristics like Insertion, Update and Deletion Anamolies. It is a multi-step process that puts data into tabular form by removing duplicated data from the relation tables.
Coding, Installation, Training, File conversion, Operation and Maintainance.
The process of ensuring that the information system is operational and then allowing users to take over its operation for use and evaluation is called implementation.
Inspection: A testing technique in which participants examine program code for predictable language specific errors.
Desk-checking: an informal process where the programmer or someone else who understands the logic of the program works through the code with a paper and pencil. The programmer executes each instruction, using test cases that may or may not be written down. In one sense, the reviewer acts as the computer, mentally checking each step and its results for the entire set of computer instructions.
Desk checking is the process of reviewing the program code to spot logic errors, which produce incorrect results.
In desk checking, the programmer follows each step in the program on paper to check whether the routine works as it is written.
because modules coexist and work with other modules in programs and systems, they must be tested together in larger groups.
Integration Testing: The process of bringing together for testing purposes all of the modules that a program comprises. Modules are typically integrated in a top-down, incremental fashion.
System testing is more than simply expanded integration testing, where you are testing the interfaces between programs in a system rather than testing the interfaces
between modules in a program. System testing is also intended to demonstrate whether a system meets its objectives.
Under a top-down approach, the coordinating module is written first.
Then the modules at the next level are written, followed by the modules at the next level, and so on, until all of the modules in the system are done.
Each module is tested as it is written.
Because top-level modules contain many calls to subordinate modules, you may wonder how they can be tested if the lower-level modules haven’t been written yet.
The answer is stub testing. Stubs are two or three lines of code written by a programmer to stand in for the missing modules. During testing, the coordinating module calls the stub instead of the subordinate module. The stub accepts control and then returns it to the coordinating module.
Acceptance refers to the fact that users typically sign off on the system and “accept” it once they are satisfied with it. The purpose of acceptance testing is for users to determine whether the system meets their requirements. The extent of acceptance testing will vary with the organization and with the system in question. The most complete acceptance testing will include alpha testing, (also called mock client testing), where simulated but typical data are used for system testing; beta testing, in which
live data are used in the users’ real working environment; and a system audit conducted by the organization’s internal auditors or by members of the quality assurance group.
Acceptance Testing Involves:
Alpha Testing [Verification Testing]: User testing of a completed IS using simulated data.
Beta Testing [Validation testing]: User testing of a completed IS using real data in the real user environment.
Advantages:
Low cost
May be the only possible approach if new and existing systems cannot coexist in some form.
Risks:
It may take too long to restore old system, if necessary
time consuming
On a specified date, users stop using the old system and the new system is put into use.
Advantages:
New systems can be checked against old systems
Limits potential damage and potential cost by limiting the effects to a single site.
Impact of operational errors are minimized because old system is also processing all data
Risks:
Very expensive because of duplication of effort to run and maintain two systems
Can be confusing to users
Most costly
The burden on employees of virtually doubling their workload during conversion.
The parallel operation changeover method requires that both the old and the new information systems operate fully for a specified period. Data is input into both systems, and output generated by the new system is compared with the equivalent output from the old system. When users, management, and the IT group are satisfied that the new system operates correctly, the old system is terminated.
The most obvious advantage of parallel operation is lower risk.
Advantages:
Each phase is small and more manageable; less expensive
One advantage of a phased approach is that the risk of errors or failures is limited to the implemented module only.
allowing users to get used to the system gradually, the possibility of detecting and recovering from errors without a lot of down time, and the ability to
add features one-by-one
Risk:
Extra bridging
At a branch office or department or factory
Advantages:
Reduced risks/ limits potential harm and costs
Less expensive
Risk:
Burden on IS staffs, some could benefit earlier than others.
System documentation can be further divided into internal and external documentation.
Internal documentation= part of the program source code or is generated at compile time.
External documentation= System documentation that includes the outcome of structured diagramming techniques such as DFD and ER diagrams.
Whereas system documentation is intended primarily for maintenance programmers, user documentation is intended mainly for users.
User Documentation: consists of instructions and information to users who will interact with the system and includes user manuals, Help screens, and tutorials.
User documentation (such as user manuals, training manuals, and online help systems) is designed to help the user operate the system.
There are three fundamentally different types of user documentation:
Reference documents, procedures manuals, and tutorials.
What training should you provide to the system users? It’s obvious: how to use the system. The training should cover all the capabilities of the new system, so that users understand what each module does, right?
Wrong. Training for business systems should focus on helping the users to accomplish their jobs, not on how to use the system.
E-learning: a formalized learning system designed to be carried out remotely, using computer-based electronic communication.
==delivered over Internet, inexpensive, available anytime and anywhere, possible to learn at ones pace,
E-learning systems can make available several different elements that enhance the learning experience, including simulations, online access to mentors and experts, e-books, net meetings, and video on-demand
Software help components: —they embed training directly into a software package Eg. On-line tutorial, contain reference material, contain an expert system that acts as a coach, user doesn’t have to leave the system to get training
An information center is an organizational unit which answers questions and assist users
HELP DESK==A single point of contact for all user inquiries and problems about a particular information system or for all users in a particular department.
=========the center of support activities for a specific information system in many organizations
======is an information systems department function, staffed by IS personnel.
======provides a place for a user to talk with a person who can answer questions (usually over the phone, but sometimes in person).