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System analysis

System Analysis full chapter with detailed

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System analysis

  1. 1. 5-1
  2. 2. Presented By:Presented By: Shahban IqbalShahban Iqbal 5-2
  3. 3. What is Systems Analysis ? Systems analysis – a problem-solving technique that decomposes a system into its component pieces for the purpose of studying how well those component parts work and interact to accomplish their purpose. 5-3
  4. 4. Context of Systems Analysis 5-4
  5. 5. System Analysis ApproachesSystem Analysis Approaches Model-Driven Analysis Methods Model-driven architecture (MDA) is a software  design approach for the development of software systems.  It provides a set of guidelines for the structuring of  specifications, which are expressed as models. • Unified Modeling Language (UML) • Object-Oriented Approach 5-5
  6. 6. A Simple Object Model 5-6
  7. 7. Accelerated Systems Analysis Accelerated systems analysis is a problem solving  technique that decomposes a system into several  components in order to identify how these  components work and interact 5-7
  8. 8. Requirements Discovery Requirements discovery – the process, used by systems analysts of  identifying or extracting system problems and solution requirements  from the user community.  5-8
  9. 9. Requirements Discovery Methods • Fact-finding – the process of collecting information about  system problems, opportunities, solution requirements, and  priorities.  • Joint requirements planning (JRP) –use of facilitated  workshops to bring together all of the system owners, users,  and analysts, and some systems designer and builders to  jointly perform systems analysis.  5-9
  10. 10. Business Process Redesign Business process reengineering (BPR) is the  practice of rethinking  and redesigning the way work is  done to better support an  organization's mission and  reduce costs. 5-10
  11. 11. FAST Systems Analysis Phases • Scope Definition Phase • Is the project worth looking at? • Problem Analysis Phase • Is a new system worth building? • Requirements Analysis Phase • What do the users need and want from the new system? • Logical Design Phase • What must the new system do? • Decision Analysis Phase • What is the best solution? 5-11
  12. 12. 5-12
  13. 13. The Scope Definition Phase • Define the scope of the problem, perceived problems, opportunities, and directives that triggered the project • Must establish the project plan on terms of scale, development strategy, schedule, resource requirements and budget. • Scope Definition Phase consists of five tasks 1.Identify Baseline Problems and Opportunities 2.Negotiate Baseline Scope 3.Assess Baseline Project Worthiness 4.Develop Baseline Schedule and Budget 5.Communicate the Project Plan 5-13
  14. 14. Tasks for the Scope Definition Phase 5-14
  15. 15. Identify Baseline Problems and Opportunities • after baseline is established, each problem, opportunity, and directive is assessed with respect to urgency, visibility, tangible benefits, and priority. • Leaders: Senior System Analysts or Project Manager • Key Deliverable: Preliminary Problem Statement • Primary Technique: fact-finding and meetings with system owners 5-15
  16. 16. Negotiate Baseline Scope • Preliminary scope can change, potentially effecting budget and schedule • Defined in simple list, not concerned with details. • Participants: System Owners' (includes executive sponsor) managers of all other organizational units that may be effected. • Trigger: Preliminary Problem Statement • Techniques: fact-finding and meetings 5-16
  17. 17. Assess Baseline Project Worthiness • answer "Is this project worth looking at?" • "Will the value of the project offset costs incurred in development?" (best guess) • Leader: System Analyst or Project Manager, BUT the System Owner (inclusive of exec sponsor) should make the decision • Trigger: Preliminary Problem Statement with Scope. • Deliverable: go or no-go. 5-17
  18. 18. Develop Baseline Schedule and Budget • initial project plan should at least consist of a preliminary master plan (includes schedule and resource assignments for entire project) and a detailed plan and schedule for completing the next phase of the project (problem analysis phase) • Leader: Project Manager • Participants: Project Team (joint project planning) • Trigger: go or no-go; Problem Statement with Scope • Deliverable: Baseline Project Plan and Schedule • Technique: use of project management software (Microsoft Project) 5-18
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  20. 20. Communicate the Project Plan • formally launch the project and communicate the project, goals, and schedule to the entire business community; • conduct project kickoff event (open to entire business community) and create an intranet project Web site; • Leaders: Executive Sponsor jointly facilitate task with Project Manager • Techniques: Use of effective interpersonal and communication skills 5-20
  21. 21. Tasks of the Problem Analysis Phase 5-21
  22. 22. Problem Analysis Phase • Define systems analysis and relate the term to the scope definition, problem analysis, requirements analysis, logical design, and decision analysis • phases of this book's systems development methodology. Describe a number of systems analysis approaches for solving business system problems. • Problem Analysis Phase typically includes 6 tasks 5-22
  23. 23. Understand the Problem Domain • Each team member brings different vocabulary, perceptions, and opinions • Must understand problem domain • Leaders: Project Manager, facilitated by lead System Analyst • Participants: other System Analysts to conduct interviews, scribe for meetings, and document findings; representative from owners and users from all supporting or impacted business units • Trigger: Approval to Continue the Project 5-23
  24. 24. Analyze Problems and Opportunities • analyze the problem for causes and effects before stating any possible solution • Leaders: System Analysts • Participants: Owners and Users should actively participate in C and E analysis • Deliverable: Updated Problem Statements and Cause-And-Effect Analysis for each problem and opportunity ( Problems, Opportunities, Objectives, and Constraints Matrix) • Techniques: fact-finding and JRP 5-24
  25. 25. Analyze Business Processes • Measure value added or subtracted by process as it relates to the total organization • owners and users can become defensive of existing business processes, analysts must keep focus on processes not people who perform them • Leader: One or more System Analysts or Business Analysts ideally trained, experienced, or certified in BPR • Participants: Owners and Users • Trigger: Only some Problem Domain knowledge 5-25
  26. 26. 5-26
  27. 27. Establish System Improvement Objectives • purpose is to establish the criteria against which any improvements to the system will be measured (objectives). • identify any constraints that may limit flexibility in achieving those improvements; • objectives establish expectations for any new system. 5-27
  28. 28. Update or Refine the Project Plan • New system may be larger than original expected, may have to reduce scope to meet deadline • Deliverable: Updated Project Plan with detailed plan for next phase to follow 5-28
  29. 29. Communicate Findings and Recommendations • communicate to entire business community; • Leaders: Project Manager and Executive Sponsor jointly facilitate • Trigger: Updated Project Plan • Deliverable: report , verbal presentation, or inspection and essential elements combined into the System Improvements Objectives • Techniques: interpersonal and communications skills 5-29
  30. 30. Requirements Analysis Phase Tasks 5-30
  31. 31. Requirements Analysis Phase • Requirements analysis, also called requirements engineering, is the process of determining user expectations for a new or modified product. • These features, called requirements, must be quantifiable, relevant and detailed. In software engineering, such requirements are often called functional specifications. 5-31
  32. 32. Requirements Analysis Phase Tasks • Identify and Express System Requirements • Prioritize System Requirements • Update or Refine the Project Plan • Communicate the Requirements Statements 5-32
  33. 33. Requirements Analysis Phase Functional requirement – a description of activities and services a system must provide. • inputs, outputs, processes, stored data Nonfunctional requirement – a description of other features, characteristics, and constraints that define a satisfactory system. 5-33
  34. 34. Key Terms of Requirements Analysis Phase Time boxing – a technique that delivers information systems functionality and requirements through versioning. 1. The development team selects the smallest subset of the system that, if fully implemented, will return immediate value to the systems owners and users. 2. That subset is developed, ideally with a time frame of six to nine months or less. 3. Subsequently, value-added versions of the system are developed in similar time frames. • A mandatory requirement is one that must be fulfilled by the minimal system, version 1.0 • A desirable requirement is one that is not absolutely essential to version 1.0. It may be essential to the vision of a future version. 5-34
  35. 35. Tasks for Logical Design Phase 5-35
  36. 36. Logical Design Phase • A logical design is a conceptual, abstract design. You do not deal with the physical implementation details yet • you deal only with defining the types of information that you need. • The process of logical design involves arranging data into a series of logical relationships called entities and attributes. 5-36
  37. 37. Logical Design Phase Tasks 1. Structure Functional Requirements 2. Prototype Functional Requirements 3. Validate Functional Requirements 4. Define Acceptance Test Cases 5-37
  38. 38. Logical Design Phase • The logical design of a system pertains to an abstract representation of the data flows, inputs and outputs of the system. • To represent the logical design of a system we can use different diagrams like Entity Relationship Diagram 5-38
  39. 39. Tasks for Decision Analysis Phase 5-39
  40. 40. Decision Analysis Phase • Define systems analysis and relate the term to the scope definition, problem analysis, requirements analysis, logical design. • Decision analysis phases is a systems development methodology. Describe a number of systems analysis approaches for solving business system problems. 5-40
  41. 41. Decision Analysis Phase Tasks 1. Identify Candidate Solutions 2. Analyze Candidate Solutions 3. Compare Candidate Solutions 4. Update the Project Plan 5. Recommend a System Solution 5-41
  42. 42. Key Terms of Decision Analysis Phase • Technical feasibility – Is the solution technically practical? Does our staff have the technical expertise to design and build this solution? • Operational feasibility – Will the solution fulfill the users’ requirements? To what degree? How will the solution change the users’ work environment? How do users feel about such a solution? • Economic feasibility – Is the solution cost-effective? • Schedule feasibility – Can the solution be designed and implemented within an acceptable time period? 5-42
  43. 43. Typical System Proposal Outline 5-43 I. Introduction A. Purpose of the report B. Background of the project leading to this report C. Scope of the report D. Structure of the report II. Tools and techniques used A. Solution generated B. Feasibility analysis (cost-benefit) III. Information systems requirements IV. Alternative solutions and feasibility analysis V. Recommendations VI. Appendices
  44. 44. Thank You 5-44

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