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CHAPTER 3 SYSTEM ANALYSIS - Coggle Diagram

- - - - -Outputs
        
        –The Web site must report online volume statistics every four hours, and hourly during peak periods.
        
        –The contact management system must generate a daily reminder list for all sales reps.
        
        –The purchasing system must provide suppliers with up-to-date specifications
      - -Inputs
        
        –Manufacturing employees must swipe their ID cards into online data collection terminals that record labor costs and calculate production efficiency.
        
        –Student grades must be entered on machine-scannable forms prepared by the instructor.
        
        –Each input form must include date, time, product code, customer number, and quantity.
      - –Processes
        
        –The student records system must calculate the GPA at the end of each semester.
        
        –The human resources system must interface properly with the existing payroll system.
      - –Performance
        
        –The system must support 25 users online simultaneously.
        
        –Response time must not exceed four seconds.
        
        –The system must be operational seven days a week, 365 days a year.
      - –Controls
        
        –The system must provide logon security at the operating system level and at the application level.
        
        –The system must maintain separate levels of security for users and the system administrator.
        
        –The system must create an error log file that includes the error type, description, and time.
  - - - –Zachman Framework for Enterprise Architecture
      - –Helps managers and users understand the model and assures that overall business goals translate into successful IT projects
    - - –Interviews
        •After you identify the information you need, you can begin the interviewing process, which consists of seven steps for each interview:
        
        –Step 1 : Determine the people to interview.
        
        –Informal structures
        
        –Step 2 : Establish objectives for the interview.
        
        –Determine the general areas to be discussed
        
        –List the facts you want to gather
        
        –Step 3 : Develop interview questions.
        
        –Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents
        
        –Step 4 : Prepare for the interview.
        
        –Careful preparation is essential because an interview is an important meeting and not just a casual chat
        
        –Step 5 : Conduct the interview.
        
        –Develop a specific plan for the meeting
        
        –Allow the person enough time to think about the question
        
        –Step 6 : Document the interview.
        
        –Note taking should be kept to a minimum
        
        –After conducting the interview, you must record the information quickly
        
        –Step 7 : Evaluate the interview.
        
        –In addition to recording the facts obtained in an interview, try to identify any possible biases
      - –Documentation review
        
        •Document review can help you understand how the current system is supposed to work.
        
        •If the system uses a software package, you should review the documentation for that software.
      - –Observations
        
        •Seeing the system in action gives you additional perspective and a better understanding of the system procedures
        
        •Plan your observations in advance by preparing a checklist of specific tasks you want to observe and questions you want to ask.
      - –Questionnaires
        
        •In projects where it is desirable to obtain input from a large number of people, a questionnaire can be a valuable tool.
        
        •The heading usually is followed by general instructions that provide clear guidance on how to answer the questions.
        
        Type of questions
        
        –Open-ended questions
        
        –Close-ended questions
      - –Sampling
        
        •When studying an information system, you should collect examples of actual documents using a process called sampling.
        
        Sampling techniques include:
        
        –Systematic sampling
        
        •A systematic sample would select every tenth customer for review.
        
        –Stratified sampling
        
        •If you want to ensure that the sample is balanced geographically, however, you could use a stratified sample to select five customers from each of four zip codes.
        
        –Random sampling
        
        •A random sample selects any 20 customers.
      - –Research
        
        •Research is another important fact-finding technique.
        
        •Research also can involve a visit to a physical location, called a site visit, where the objective is to observe a system in use at another location.
  - - - –Step 1 : Review the questions
        
        The questions generated before the information was gathered should be reviewed.
      - –Step 2 : Organize the information
        
        There is a certain logic that can be followed.
        
        –Gather together all relevant information that has been collected.
        
        –If necessary, sort information into parts which belong together.
        
        –Some may have already been analyzed.
        Some may be partly analyzed, and some may need analysis.
      - –Step 3 : Decide how to analyze the information
        
        Analysis of parts may be simply adding up numbers and averaging them or comparing information to examine the relationship of one thing to another, or two things together.
      - –Step 4 : Analyze quantitative information
        
        It is likely that quantitative (numbers) information will be computed by hand, or with the use of adding machines.
        
        Two straightforward ways to analyze information;
        
        –Tally Sheets
        
        –Summary Sheets.
      - –Step 5 : Analyze qualitative information
        
        •Analysis of qualitative (descriptive) information is a creative and critical process.
        
        •The way the information has been gathered will probably determine how it can be analyzed.
      - –Step 6 : Integrate the information
        
        •Involves graphical methods and nontechnical language that represent the system at various stages of development
        
        To help them understand system requirements, analysts use
        
        –Functional Decomposition Diagrams (FDD)
        
        –Unified Modeling Language (UML) diagrams.
  - - - –Functional Decomposition Diagrams (FDD)
      - –Unified Modeling Language (UML) diagrams.
  - - - Ude case modellin
        
        •Actor
        
        •Symbol for a use case is an oval with a label that describes the action or event
        
        •Use cases also can interact with other use cases
        
        •When the outcome of one use case is incorporated by another use case, we say that the second case uses the first case
    - - Include symbols that represent
        
        •Classes
        
        •Lifelines
        
        •Messages
        
        •Focuses
- - - - –Process symbol
        •Receives input data and produces output that has a different content, form, or both
        •Contain the business logic, also called business rules
      - -Data flow symbol
        •Represents one or more data items
        •The symbol for a data flow is a line with a single or double arrowhead
      - –Data store symbol
        •Represent data that the system stores
        •The physical characteristics of a data store are unimportant because you are concerned only with a logical model
      - –Entity Symbol
        •Name of the entity appears inside the symbol
        •Shows only external entities that provide data to the system or receive output from the system.