1 / 54

SYSTEMS ANALYSIS & DESIGN

SYSTEMS ANALYSIS & DESIGN. PHASE 2 SYSTEMS ANALYSIS Determining Requirements. SDLC Phases. Phase 2: Systems Analysis Objectives Learn how the current system works Determine and document fully how the system could work better Develop a logical model of the new system

sidone
Télécharger la présentation

SYSTEMS ANALYSIS & DESIGN

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. SYSTEMS ANALYSIS & DESIGN PHASE 2 SYSTEMS ANALYSIS Determining Requirements

  2. SDLC Phases Phase 2: Systems Analysis Objectives • Learn how the current system works • Determine and document fully how the system could work better • Develop a logical model of the new system • Make recommendations to management

  3. Chapter 3 Determining Requirements

  4. Objectives • Explain how systems analysis relates to business needs, problems, and opportunities • List and describe the types of system requirements that must be identified during systems analysis • Describe how to conduct a successful interview

  5. Objectives • Explain when and how to use fact-finding techniques, including interviews, documentation review, observation, questionnaires, sampling, and research • Set up effective documentation methods to use during systems development

  6. Objectives • Describe alternative systems development approaches, including joint application development (JAD) and rapid application development (RAD) • Explain object-oriented (O-O) systems development and how this approach differs from structured analysis and design

  7. Overview of systems analysis phase Fact-finding techniques Interviewing Documentation review Observation Questionnaires Sampling Research Methods used to record results Introduction

  8. Click to see Figure 3-1 Overview of the Systems AnalysisPhase • Systems analysis phase tasks • Gather and record facts about the current system and what is required to support business needs • Three-step approach to decision-making • Determine the facts • Analyze the facts • Make a decision • Two steps in the systems analysis phase • Requirements determination (fact-finding) • Requirements analysis

  9. The Challenge of Systems Analysis • Large systems are especially challenging • Business systems must change rapidly • Systems analysts use various skills • Reverse engineering • Critical-thinking skills • Interpersonal skills

  10. Click to see Figure 3-2 The Challenge of Systems Analysis • Requirements determination questions • Who does it? • What is done? • Where is it done? • When is it done • How is it done • Another important question • Why?

  11. The Challenge of Systems Analysis • Requirements analysis questions • Who should do it? • What should be done? • Where should it be done? • When should it be done? • How should it be done?

  12. Systems Requirements • Characteristics or features that must be included to satisfy business requirements • Outputs • Inputs • Processes • Timing • Controls • Volumes. sizes, and frequencies

  13. Interviews • Determine the people to interview • Establish objectives for the interview • Prepare for the interview • Conduct the interview • Document the interview • Evaluate the interview • Unsuccessful interviews

  14. Click to see Figure 3-3 Interviews • Determine the people to interview • Select the right people • Consider informal structures

  15. Interviews • Establish objectives for the interview • Determine the areas to be discussed • List the facts you want to gather • Solicit ideas, suggestions, and opinions • Keep questions consistent

  16. Click to see Figure 3-4 Interviews • Prepare for the interview • Schedule a specific day and time • Place a reminder call • Send a memo to managers

  17. Click to see Figure 3-5 Interviews • Prepare for the interview • Schedule a specific day and time • Place a reminder call • Send a memo to managers • Create a list of questions • Use a variety of questions • Open-ended questions • Closed-ended questions • Range of responses questions • Send confirmation memo to interviewee

  18. Interviews • Conduct the interview • Introduce yourself • Describe the project • Explain your objectives • Ask questions in order • Summarize the main points • Explain the next course of action • Listen carefully - practice engaged listening

  19. TRADEOFF • What is the best location for the interview? • Interviewee’s office • Makes the interviewee more comfortable • Easier access to supporting material • Neutral location • Fewer interruptions • Advise interviewee to bring necessary items

  20. A KEY QUESTION • Does organization level affect interviews? • At FastPak, Jesse Evans runs into a problem • Calls and visitors cause many interruptions • Interview process is time-consuming • Manager unwilling to reschedule meeting • What should Jesse do in this situation?

  21. Interviews • Document the interview • Keep note-taking to a minimum • Record the information quickly • Allow time between interviews • Thank the interviewee with a memo • Note the date, time, location, and purpose • Review the main points discussed

  22. Interviews • Evaluate the interview • Identify possible biases • Determine whether interviewees have necessary experience

  23. TRADEOFF • Tape recorders: pros and cons • Can be an effective tool • If people feel threatened • Discuss in advance • Reassure the interviewee • Turn off tape when indicated • Must use this technique carefully • You might rely too much on the recorder • Extra time needed to listen to taped material

  24. A KEY QUESTION • Should an analyst interview several people at the same time? • Jesse’s problem in the FastPak interview • One person dominated the conversation • Meeting with two interviewees created a problem, not an opportunity • What should Jesse have done?

  25. Interviews • Unsuccessful interviews • Not all interviews are successful • Find a way to conclude an unsuccessful meeting • Consider alternatives

  26. Other Fact-Finding Techniques • Document review • Observation • Questionnaires • Sampling work and work products • Graphics • Research

  27. Other Fact-Finding Techniques • Document review • Review existing system documentation • Obtain copies of actual forms and documents • Review blank copies of forms • Review samples of completed forms • Review software documentation

  28. Click to see Figure 3-6 Other Fact-Finding Techniques • Observation • Ask questions about present system operation • Observe all steps in the processing cycle • Examine each form, record, and report • Consider each person working with the system • Talk to people who receive current reports • Consider the Hawthorne Effect

  29. Click to see Figure 3-7 Other Fact-Finding Techniques • Questionnaires • Brief and user-friendly • Clear instructions • Questions in logical order • Simple wording to avoid misunderstanding • Avoid leading questions • Open-ending questions are difficult to tabulate • Limit questions raising concern/negative issues • Section for general comments • Test the questionnaire in advance

  30. Other Fact-Finding Techniques • Sampling work and work products • Collect examples of actual documents • Sampling techniques • Systematic sample • Stratified sample • Random sample

  31. Click to see Figure 3-8 Click to see Figure 3-9 Other Fact-Finding Techniques • Graphics • Display fact-finding results graphically • Graphical format can highlight quality control problems/causes • Histogram is common tool to display questionnaire or sampling results

  32. Click to see Figure 3-10a Click to see Figure 3-10b Other Fact-Finding Techniques • Research • Journals, periodicals, books • Internet sites • Hardware and software vendors • Independent firms that provide information • Newsgroups • Professional meetings, seminars, discussions • Site visits to observe a system in use

  33. TRADEOFF • Interviews • Work best with small number of people • More personal and familiar than questionnaires • People talk more freely in person • Interviewers can react immediately • Participation can be a human relations plus • Costly and time-consuming

  34. TRADEOFF • Questionnaires • Work best with large groups • Many people have opportunity for input • More convenient for recipients • Anonymous responses might be more candid • Questions must be designed carefully • Some recipients view questionnaires as intrusive, time-consuming, and impersonal

  35. A KEY QUESTION • Conduct interviews or send questionnaires? • Cyberstuff background • Several thousand sales transactions per week • Three-shift operation • 50 full-time and 125 part-time employees • Ann’s objective: information to analyze and resolve recent billing complaint problems • What are pros and cons of each technique? • What is the best way to select participants?

  36. Recording the Facts • The need for recording the facts • Keeping accurate records is essential • Basic rule: write it down • Guidelines for good documentation • Record information as soon as possible • Use the simplest recording method • Ensure that your work is understandable • Organize your documentation material • Consider a narrative list with simple statements

  37. Recording the Facts • Software tools • Word processing • Spreadsheets • Database • Presentation graphics • Personal or desktop information managers

  38. Other Systems DevelopmentTechniques • Introduction • Structured analysis and design is the most common method • Other techniques are available • Joint application development (JAD) • Rapid application development (RAD) • Object-oriented (O-O) systems development

  39. Click to see Figure 3-11 Other Systems DevelopmentTechniques • Joint application development (JAD) • Task force of users, managers, and IS staff • Objectives • Gather information • Discuss business needs • Define the new system requirements • Methods • Team usually meets at specific location • Team has project leader and recorder(s) • Key users participate in intense development effort • JAD can be costly, but highly effective

  40. Other Systems DevelopmentTechniques • Rapid application development (RAD) • Team method similar to JAD, but goes further • RAD phases resemble a mini-SDLC • Requirements planning, user design, construction, and cutover • RAD involves a continuous design process • Team can react quickly • Final objective is a functioning system • RAD can be faster and less costly, but stresses system mechanics rather than strategic needs

  41. Other Systems DevelopmentTechniques • Object-oriented (O-O) systems development • Object-based model • Objects and their attributes are abstract entities • Classes and subclasses

  42. Preview of Requirements Analysis Phase • Requirements analysis is the second major stage of the systems analysis phase • Requirements analysis objectives • Develop a logical design of the system • Create a system requirements document • Deliver a formal presentation to management

  43. SOFTWEAR, LIMITED • SWL has completed a preliminary investigation • Several problems were revealed • Input errors • Overtime to correct errors and produce reports • The IS team recommended further analysis • Mr. Jeremy approved the recommendation • The systems analysis phase now is underway

  44. Click to see Figure 3-12 Click to see Figure 3-13 SOFTWEAR, LIMITED • Human resources department interview • Review of organization charts

  45. Click to see Figure 3-14 Click to see Figure 3-15 SOFTWEAR, LIMITED • Human resources department interview • Review of organization charts • Interview with Meredith Rider • Preparation

  46. Click to see Figure 3-16 Click to see Figure 3-18 Click to see Figure 3-17 Click to see Figure 3-19 Click to see Figure 3-20 SOFTWEAR, LIMITED • Human resources department interview • Review of organization charts • Interview with Meredith Rider • Preparation • Forms

  47. Click to see Figure 3-21 Click to see Figure 3-22 SOFTWEAR, LIMITED • Human resources department interview • Review of organization charts • Interview with Meredith Rider • Preparation • Forms • Explanatory memo to Mike Feiner • Confirmation memo to Meredith • Follow-up memo to Meredith after interview

  48. Click to see Figure 3-23 SOFTWEAR, LIMITED • Payroll department interview • Interview with Nelson White, lead payroll clerk • Review of SWL’s Systems and Procedures Manual

  49. Click to see Figure 3-24 SOFTWEAR, LIMITED • Payroll department interview • Interview with Nelson White, lead payroll clerk • Review of SWL’s Systems and Procedures Manual • Review of sample payroll deduction registers

  50. SOFTWEAR, LIMITED • Business information services interview • Interview with Linda DeMarco, customer relations manager for BIS • New program called CHIPS • Determination that CHIPS will not handle SWL’s needs

More Related