system development life cycle

1. System Development Life
Cycle(SDLC)

2.  A frame work that describe the activities
performed at each stage of software
development project

4.  It can be environmental based or organizational based.
 Ideas are generated to advance technology.
 User originated ideas prompt initial investigation.

5.  Economic: Cost benefit analysis.
 Technical: We need to check whether existing computer
can support the system.
 Behavioral: An estimate should be made of how strong a
reaction the user staff is likely to have toward the
development of a computerized system.

6.  Form a project team and appoint a leader.
 Prepare System flowcharts.
 Describe and identify characteristics of candidate system.
 Evaluate performance.
 Select best candidate system.

7.  In the Analysis stage an in-depth analysis is performed to
obtain a detailed understanding of the business needs.
 Tools Used: DFD’s, interviews, on-site observation,
questionnaire etc.
 Training, experience and common sense are required for
collecting information to do analysis.

8.  Two phases:
 Logical Design: Specifies user needs(mental work).
 Physical Design: Tells the programmer what the
candidate system must do (usually paper work).

9.  The objective of coding phase is to transform the design
of system in to code in a high-level language using coding
standards.

10.  three type of testing;
 Unit testing
 One by one each code(modules)
 Integration testing
 Individual software modules as a group
 System testing
 testing conducted on a complete, integrated system to evaluate the system's
compliance with its specified requirements.

11.  judge the client knowledge about software.
 User personnel's are trained to operate the system

12.  It is of 3 types:
1. replace a manual system.
2. A new computer system to replace an existing one.
3. modified application to replace existing one on same
computer.

13.  The Post-Implementation Review is used to evaluate the
effectiveness of the system.
 The objectives are to determine if the system does what it
is designed to do
 Does it support the user as required in an effective and
efficient manner
 The review should assess how successful the system is in
terms of functionality, performance, and cost versus
benefits

14.  This phase is to ensure :
 that needs continue to be met and that the system
continues to perform according to specifications.
 Routine hardware and software maintenance and
upgrades .
 User training continues during this phase, as needed, to
acquaint new users to the system or to introduce new
features to current users.

15.  What is feasibility?
 Why analysis is required?
 Difference b/w physical & logical design?