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CHAPTER 3 : SYSTEM ANALYSIS - Coggle Diagram

- - - - The Web site must report online volume statistics every four hours, and hourly during peak periods.
    - - Manufacturing employees must swipe their ID cards into online data collection terminals
    - - The student records system must calculate the GPA at the end of each semester.
    - - The system must provide logon security at the operating system level and at the application level.
    - - The system must support 25 users online simultaneously.
- - - - 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.
        Step 2 : Establish objectives for the interview.
        Step 3 : Develop interview questions.
        Step 4 : Prepare for the interview.
        Step 5 : Conduct the interview.
        Step 6 : Document the interview.
        Step 7 : Evaluate the interview.
    - - Document review can help you understand how the current system is supposed to work.
    - - Consider the following issues when you prepare your list:
        
        1.Ask sufficient questions to ensure that you have a complete understanding of the present system operation.
        2.Observe all the steps in a transaction and note the documents, inputs, outputs, and processes involved.
        3.Examine each form, record, and report.
        4.Consider each user who works with the system
        5.Talk to the people who receive current reports to see whether the reports are complete, timely, accurate, and in a useful form
      - Seeing the system in action gives you additional perspective and a better understanding of the system procedures
    - - In projects where it is desirable to obtain input from a large number of people, a questionnaire can be a valuable tool.
      - Types of Question
        
        Open-ended question
        
        Close-ended question
    - - When studying an information system, you should collect examples of actual documents using a process called sampling.
      - Sampling Technique Include
        
        1.Systematic sampling
        2.Stratified sampling
        3.Random sampling
    - - Research is another important fact-finding technique
- - - - -Receives input data and produces output that has a different content, form, or both
        -Contain the business logic, also called business rules
        -Referred to as a black box
    - - -Represents one or more data items
        -The symbol for a data flow is a line with a single or double arrowhead
        -Avoid-
        1.spontaneous generation
        2.Black hole
        3.Gray hole
    - - -Represent data that the system stores
        -The physical characteristics of a data store are unimportant because you are concerned only with a logical model
    - - -Name of the entity appears inside the symbol
        -Shows only external entities that provide data to the system or receive output from the system.
  - - - -Draw the context diagram so that it fits on one page
        -Use the name of the information system as the process name in the context diagram
        -Use unique names within each set of symbols
        -Do not cross lines
        -Provide a unique name and reference number for each process
        -Obtain as much user input and feedback as possible
    - - Step 1 : Draw a context diagram
      - Step 2: Draw a Diagram 0 DFD
      - Step 3: Draw the Lower-Level Diagrams
- - - - A functional decomposition diagram (FDD) is a top-down representation of a function or process.
    - - The Unified Modeling Language (UML) is a widely used method of visualizing and documenting software systems design.
      - UML provides various graphical tools, such as ;
        
        use case diagram
        
        sequence digram
        
        Include symbols that represent :
        1.Classes
        2.Lifelines
        3.Messages
        4.Focuses
- - - - The three structures are called
        -sequence
        -selection
        -iteration
    - - Must conform to the following rules
        -Use only the three building blocks of sequence, selection, and iteration
        -Use indentation for readability
        -Use a limited vocabulary, including standard terms used in the data dictionary and specific words that describe the processing rules
    - - 4 Types of tables;
        -Tables with one condition
        -Tables with two condition
        -Tables with three condition
        -Table with multiple outcomes