1. System Development Fundamentals System Analysis and Design (INF123) Semester B Lecturer: O. Pelekanou Weeks 4-5

2. Phase Description Systems analysis is the second of five phases in the systems development life cycle (SDLC) Uses requirements modeling and enterprise modeling to represent the new system Before proceeding to the next phase, systems design, you will consider system development strategies

3. Objectives Describe systems analysis phase activities and the end product of the systems analysis phase Understand joint application development (JAD) and rapid application development (RAD) Explain how systems analysts use a functional decomposition diagram (FDD) Describe the Unified Modeling Language (UML) and explain use case diagrams and sequence diagrams

4. Objectives List and describe system requirements, including outputs, inputs, processes, performance, and controls Explain the importance of scalability in system design The deliverable is a system requirements document (The end product for the systems analysis phase. It is an overall design for the new system.)system requirements document

5. Chapter Objectives Define total cost of ownership (TCO) and explain the concept Conduct a successful interview Develop effective documentation methods to use during systems development

6. Introduction This chapter describes requirements modeling techniques and team-based methods that systems analysts use to visualize and document new systems The chapter then discusses system requirements and fact-finding techniques, which include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research

7. Systems Analysis Phase Overview Uses models and other documentation tools to visualize and describe the proposed system The deliverable is a system requirements document (The end product for the systems analysis phase. It is an overall design for the new system.)system requirements document Figure 3-1

8. Systems Analysis Phase Overview Systems Analysis Skills –Analytical skills (Skills that help one recognize a problem, evaluate the key elements, and a useful solution)Analytical skills –Interpersonal skills ("People" skills that help a system analyst work with personnel at all organizational levels, and balance sometimes conflicting user needs.)Interpersonal skills Team-Oriented Methods and Techniques –Joint application development (JAD)Joint application development (JAD) joint application development (JAD). JAD is a team-oriented technique for fact-finding and requirements modeling. –Rapid application development (RAD)Rapid application development (RAD) –rapid application development (RAD)RAD resembles a condensed version of the entire SDLC, with users involved every step of the way.

9. Modeling Tools and Techniques CASE Tools –Offer powerful modeling features –System analysts use modeling and fact-finding interactively Functional Decomposition Diagrams –Functional decomposition diagram (FDD) (A top-down representation of business functions and processes. Also called structure charts.)Functional decomposition diagram (FDD) Figure 3-2 Figure 3-3

10. Modeling Tools and Techniques Unified Modeling Language –Provides various graphical tools and techniques –Use case diagramsUse case diagrams Actor –Sequence diagramsSequence diagrams Figure 3-4 Figure 3-5 Figure 3-6 Figure 3-7

12. System Requirements Checklist System requirement (A characteristic or feature that must be included in an information system to satisfy business requirements and be acceptable to users.)System requirement Five general categories –Outputs –Inputs –Processes –Performance –Controls

13. System Requirements Checklist Outputs –The Web site must report online volume statistics every four hours, and hourly during peak periods –The inventory system must produce a daily report showing the part number, description, quantity on hand, quantity allocated, quantity available, and unit cost of all parts — sorted by part number

14. System Requirements Checklist Inputs –Manufacturing employees must swipe their ID cards into online data collection terminals that record labor costs and calculate production efficiency –The department head must enter overtime hours on a separate screen

15. System Requirements Checklist Processes –The student records system must allow record access by either the student name or the student number –As the final step in year-end processing, the payroll system must update employee salaries, bonuses, and benefits and produce tax data required by the IRS

16. System Requirements Checklist Performance –The system must support 25 users online simultaneously –Response time must not exceed four seconds

17. System Requirements Checklist Controls –The system must provide log-on security at the operating system level and at the application level –An employee record must be added, changed, or deleted only by a member of the human resources department

18. Future Growth, Costs, and Benefits Scalability (The ability to adjust system capacity as business requirements change in the future.)Scalability –A scalable system offers a better return on the initial investment –To evaluate, you need information about projected future volume for all outputs, inputs, and processes

19. Future Growth, Costs, and Benefits Total Cost of Ownership –Total cost of ownership (TCO) is especially important if the development team is evaluating several alternativesTotal cost of ownership (TCO) –One problem is that cost estimates tend to understate indirect costs –Rapid Economic Justification (REJ)Rapid Economic Justification (REJ)

20. Fact-Finding Overview –The first step is to identify the information you need –Start with a fact-finding plan Who, What, Where, When, How, and Why? –Difference between asking what is being done and what could or should be done

21. Fact-Finding The Zachman Framework –Zachman Framework for Enterprise ArchitectureZachman Framework for Enterprise Architecture Figure 3-8

22. Interviews Systems analysts spend a great deal of time talking with people Much of that time is spent conducting interviews (A planned meeting during which information is obtained from another person.) interviews

23. Interview Step 1: Determine the People to Interview –Informal structures (Usually are based on interpersonal relationships and can develop from previous work assignments, physical proximity, unofficial procedures, or personal relationships.)Informal structures Step 2: Establish Objectives –Determine the general areas to be discussed –List the facts you want to gather Figure 3-9

24. Interviews Step 3: Develop Interview Questions –Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents –Avoid leading questions (Questions that suggest or favor a particular reply.)leading questions –Open-ended questions (Questions that allow for a range of answers. They encourage spontaneous and unstructured responses, and are useful in understanding a larger process.)Open-ended questions –Close-ended questions (Questions that limit or restrict the range of responses. Used in the interview process when specific information or fact verification is desired. )Close-ended questions –Range-of-response questions (Closed-ended questions that ask the person to evaluate something by providing limited answers to specific responses or on a numeric scale.)Range-of-response questions

25. Interviews Step 4: Prepare for the Interview –Careful preparation is essential because an important meeting and not just a casual chat –Limit the interview to no more than one hour –Send a list of topics –Ask the interviewee to have samples available Figure 3-10 Figure 3-11

26. Interviews Step 5: Conduct the Interview –Develop a specific plan for the meeting –Begin with good introduction –Use engaged listening (The ability to really concentrate on what someone is saying, and avoid the temptation to hear what is expected. Also includes noticing non-verbal communication.)engaged listening –Allow the person enough time to think about the question –Summarize main points –After interview, summarize the session and seek a confirmation

27. Interviews Step 6: Document the Interview –During the interview, note taking should be kept to a minimum –After the interview, record the information quickly –After the interview, send memo expressing appreciation, including the main points discussed so the interviewee has a written summary and can offer additions or corrections

28. Interviews Step 7: Evaluate the Interview –In addition to recording the facts obtained in an interview, try to identify any possible biases Unsuccessful Interviews –No matter how well you prepare for interviews, some are not successful

29. Other Fact-Finding Techniques Document Review Observation –Seeing the system in action gives you additional perspective and a better understanding of the system procedures –Plan your observations in advance –Hawthorne Effect (A phenomenon where employees who know they are being observed are more productive. )Hawthorne Effect

30. Other Fact-Finding Techniques Questionnaires (A document containing a number or standard questions that can be sent to many individuals. Also called a survey.) and Surveys (A document containing a number or standard questions that can be sent to many individuals. Also called a questionnaire.)QuestionnairesSurveys –When designing a questionnaire, the most important rule of all is to make sure that your questions collect the right data in a form that you can use to further your fact-finding –Fill-in form (Form used to collect data on the Internet or a company intranet.)Fill-in form Figure 3-12 Figure 3-13

32. Other Fact-Finding Techniques Sampling –Systematic sampleSystematic sample –Stratified sampleStratified sample –Random sampleRandom sample –Main objective of a sample is to ensure that it represents the overall population accurately

33. Other Fact-Finding Techniques Research –NewsgroupsNewsgroups –Site visitSite visit

34. Other Fact-Finding Techniques Interviews versus Questionnaires –Interview is more familiar and personal –If you require detailed information from only a few people, then you probably should interview each person –When you seek input from a large group questionnaire is a very useful tool –Questionnaire gives many people the opportunity to provide input and suggestions

35. Documentation The Need for Recording the Facts –Record information as soon as you obtain it –Use the simplest recording method –Record your findings in such a way that they can be understood by someone else –Organize your documentation

36. Documentation Software Tools –CASE Tools –Word processing –Spreadsheets Histogram –Databases

37. Documentation Software Tools –Presentation graphics –Personal information managers Personal information manager (PIM) Handheld computers Personal digital assistants (PDAs)

38. Preview of Enterprise Modeling At the conclusion of requirements modeling, systems developers should have clear understanding of business processes and system requirements The next step is to model the logical design of the system

39. Summary The systems analysis phase includes three activities: requirements modeling, enterprise modeling, and consideration of development strategies The main objective is to understand the proposed project and build a solid foundation for the systems design phase You identify the business-related requirements for the new information system, including outputs, inputs, processes, performance, and controls

40. Summary The fact-finding process includes interviewing, document review, observation, questionnaires, sampling, and research Systems analysts should carefully record and document factual information as it is collected, and various software tools can help an analyst visualize and describe an information system