Systems Analysis Design 5 th Edition Chapter 3

Systems Analysis & Design 5 th Edition Chapter 3 ● Requirements Modeling

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 2

Chapter 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 3

Chapter Objectives ● List and describe system requirements, including outputs, inputs, processes, performance, and controls ● Explain the importance of scalability in system design ● Use fact-finding techniques, including interviews, documentation review, observation, questionnaires, sampling, and research 4

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 5

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 6

Systems Analysis Phase Overview ● Uses models and other documentation tools to visualize and describe the proposed system ● The deliverable is a system requirements document Figure 3 -2 7

Systems Analysis Phase Overview ● Systems Analysis Skills – Analytical skills – Interpersonal skills ● Team-Oriented Methods and Techniques – Joint application development (JAD) – Rapid application development (RAD) 8

Joint Application Development ● User Involvement – Users have a vital stake in an information system and they should participate fully – Successful systems must be useroriented and users need to be involved 9

Joint Application Development ● JAD Participants and Roles Figure 3 -4 10

Joint Application Development Figure 3 -5 11

Joint Application Development ● JAD Advantages and Disadvantages – More expensive and can be cumbersome – Allows key users to participate effectively – When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system. 12

Rapid Application Development ● Is a team-based technique that speeds up information systems development and produces a functioning information system ● Relies heavily on prototyping and user involvement ● Project team uses CASE tools to build the prototypes and create a continuous stream of documentation 13

Rapid Application Development ● RAD Phases and Activities 14 Figure 3 -7

Rapid Application Development ● RAD Objectives – To cut development time and expense by involving the users in every phase of systems development – Successful RAD team must have IT resources, skills, and management support – Helps a development team design a system that requires a highly interactive or complex user interface 15

Rapid Application Development ● RAD Advantages and Disadvantages – Systems can be developed more quickly with significant cost savings – RAD stresses the mechanics of the system itself and does not emphasize the company’s strategic business needs – Might allow less time to develop quality, consistency, and design standards 16

Modeling Tools and Techniques ● CASE Tools 17 Figure 3 -8

Modeling Tools and Techniques ● Functional Decomposition Diagrams – A top-down representation of business functions and processes – Also called structure charts 18

Modeling Tools and Techniques ● Functional Decomposition Diagrams Figure 3 -9 19

Modeling Tools and Techniques ● Unified Modeling Language – A widely used method of visualizing and documenting software systems design – provides various graphical tools and techniques, such as use case diagrams and sequence diagrams 20

Modeling Tools and Techniques ● Unified Modeling Language Figure 3 -10 21

Modeling Tools and Techniques ● Unified Modeling Language Figure 3 -11 22

Modeling Tools and Techniques ● Unified Modeling Language Sequence Diagram Figure 3 -13 23

System Requirements Checklist ● System requirement ● Five general categories – Outputs – Inputs – Processes – Performance – Controls 24

Future Growth, Costs, and Benefits ● 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 25

Future Growth, Costs, and Benefits ● Total Cost of Ownership – In addition to direct costs, systems developers must identify and document indirect expenses that contribute to the total cost of ownership (TCO) – Microsoft has developed a method for measuring total costs and benefits, called Rapid Economic Justification (REJ) 26

Fact-Finding ● Overview – Although software can help you to gather and analyze facts, no program actually performs fact-finding for you – The first step is to identify the information you need 27

Fact-Finding ● Who, What, Where, When, How, and Why? Figure 3 -15 28

Fact-Finding ● The Zachman Framework – A model that asks the traditional factfinding questions in a systems development context 29

Fact-Finding Figure 3 -16 30

Interviews ● Systems analysts spend a great deal of time talking with people ● Much of that time is spent conducting interviews ● Consists of 7 steps 31

Interview ● Step 1: Determine the People to Interview – Informal structures ● Step 2: Establish Objectives – Determine the general areas to be discussed – List the facts you want to gather 32

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 – Open-ended questions – Closed-ended questions – Range-of-response questions 33

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 34

Interviews Figure 3 -18 35

Interviews Figure 3 -19 36

Interviews ● Step 5: Conduct the Interview – Develop a specific plan for the meeting – Begin with good introduction – Use engaged listening – Allow the person enough time to think about the question – Summarize main points – After interview, summarize the session and seek a confirmation 37

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 38

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 39

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 you observations in advance – Hawthorne Effect 40

Other Fact-Finding Techniques ● Questionnaires and Surveys – Keep the questionnaire brief and userfriendly – Provide clear instructions that will answer all anticipated questions – Arrange the questions in a logical order, going from simple to more complex topics 41

Other Fact-Finding Techniques ● Questionnaires and Surveys – 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 42

Other Fact-Finding Techniques ● Questionnaires and Surveys – 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 43

Other Fact-Finding Techniques ● Sampling – Systematic sample – Stratified sample – Random sample – Main objective of a sample is to ensure that it represents the overall population accurately 44

Other Fact-Finding Techniques ● Research – Newsgroups – Site visit Figure 3 -23 45

Other Fact-Finding Techniques ● Interviews versus Questionnaires – When you seek input from a large group questionnaire is a very useful tool – If you require detailed information from only a few people, then you probably should interview each person – Interview is more familiar and personal – Questionnaire gives many people the opportunity to provide input and suggestions 46

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 47

Documentation ● Software Tools – CASE tools – Word processing – Spreadsheets – Databases Figure 3 -24 48

Documentation ● Software Tools – Presentation graphics – Personal information managers 49

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 50

Chapter Summary ● The systems analysis phase includes three activities ● The main objective is to understand the proposed project and build a solid foundation for the systems design phase ● The fact-finding process includes interviewing, document review, observation, questionnaires, sampling, and research. 51

Chapter Summary ● 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 ● Chapter 3 Complete 52