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Requirements Modeling . Chapter 3. 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

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phase description
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
chapter objectives
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
chapter objectives4
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
chapter objectives5
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
introduction
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
systems analysis phase overview
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

systems analysis phase overview8
Systems Analysis Phase Overview
  • Systems Analysis Skills
    • Analytical skills
    • Interpersonal skills
  • Team-Oriented Methods and Techniques
    • Joint application development (JAD)
    • Rapid application development (RAD)
joint application development
Joint Application Development
  • User Involvement
    • Users have a vital stake in an information system and they should participate fully
    • Successful systems must be user-oriented and users need to be involved
joint application development10
Joint Application Development
  • JAD Participants and Roles

Figure 3-4

joint application development12
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.
rapid application development
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
rapid application development14
Rapid Application Development
  • RAD Phases and Activities

Figure 3-7

rapid application development15
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
rapid application development16
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
modeling tools and techniques
Modeling Tools and Techniques
  • CASE Tools

Figure 3-8

modeling tools and techniques18
Modeling Tools and Techniques
  • Functional Decomposition Diagrams
    • A top-down representation of business functions and processes
    • Also called structure charts
modeling tools and techniques19
Modeling Tools and Techniques
  • Functional Decomposition Diagrams

Figure 3-9

modeling tools and techniques20
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
modeling tools and techniques21
Modeling Tools and Techniques
  • Unified Modeling Language

Figure 3-10

modeling tools and techniques22
Modeling Tools and Techniques
  • Unified Modeling Language

Figure 3-11

modeling tools and techniques23
Modeling Tools and Techniques
  • Unified Modeling Language

Sequence Diagram

Figure 3-13

system requirements checklist
System Requirements Checklist
  • System requirement
  • Five general categories
    • Outputs
    • Inputs
    • Processes
    • Performance
    • Controls
future growth costs and benefits
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
future growth costs and benefits26
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)
fact finding
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
fact finding28
Fact-Finding
  • Who, What, Where, When, How, and Why?

Figure 3-15

fact finding29
Fact-Finding
  • The Zachman Framework
    • A model that asks the traditional fact-finding questions in a systems development context
fact finding30
Fact-Finding

Figure 3-16

interviews
Interviews
  • Systems analysts spend a great deal of time talking with people
  • Much of that time is spent conducting interviews
  • Consists of 7 steps
interview
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
interviews33
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
interviews34
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
interviews35
Interviews

Figure 3-18

interviews36
Interviews

Figure 3-19

interviews37
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
interviews38
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
interviews39
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
other fact finding techniques
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
other fact finding techniques41
Other Fact-Finding Techniques
  • Questionnaires and Surveys
    • Keep the questionnaire brief and user-friendly
    • Provide clear instructions that will answer all anticipated questions
    • Arrange the questions in a logical order, going from simple to more complex topics
other fact finding techniques42
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
other fact finding techniques43
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
other fact finding techniques44
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
other fact finding techniques45
Other Fact-Finding Techniques
  • Research
    • Newsgroups
    • Site visit

Figure 3-23

other fact finding techniques46
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
documentation
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
documentation48
Documentation
  • Software Tools
    • CASE tools
    • Word processing
    • Spreadsheets
    • Databases

Figure 3-24

documentation49
Documentation
  • Software Tools
    • Presentation graphics
    • Personal information managers
preview of enterprise modeling
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
chapter summary
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.
chapter summary52
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