Topic Two

  1. Data Flow Diagrams
    Graphically describes the flow of data within a system

    • - Entity
    • - Data flow
    • - Process
    • - Data store
  2. Entity (Square)
    Source of data/input into the system

    or

    Destination of data/output from the system
  3. Data Flows (Arrow)
    • Movement of data among
    • - Entities (source or destination)
    • - Processes
    • - Data sources
  4. Process (circle)
    Transformation of data
  5. Data Flow Diagram Levels
    • Context
    • - Highest level (most general)
    • - shows inputs and outputs into system
    • - one process symbol only, no data stores

    • Level-0
    • - shows all major activity steps of a system
    • - processes are labelled 1.0, 2.0, 3.0...

    • Level-1
    • - shows only one major activity, divided into sub-activities
    • - processes are labelled 1.1, 1.2, 1.3...
  6. Flowcharts
    Uses symbols to logically depict transaction processing and the flow of data through a system

    A pictorial representation is easier to understand and explain than a detailed narrative
  7. Flowchart Types
    • Document
    • - Flow of documents through an organisation
    • - Useful for analysing internal control procedures

    • System
    • - Logical representation of system inputs, processes and outputs
    • - Useful in systems analysis and design

    • Program
    • - Represents the logical sequence of program logic
Author
Lea_
ID
328154
Card Set
Topic Two
Description
Topic Two
Updated