SAD 4

• Systems Analysis and Design

  • Introduction
  • Project Initiation
  • Requirements Gathering
  • Process Modelling
  • Data Modelling
  • System Design
  • System Implementation
  • Project Management in Systems Development
  • Agile and Iterative Development
  • Emerging Trends in Systems Analysis and Design
• Process modelling


  A technique used in Systems Analysis and Design to visually represent the flow of activities, data, and interactions within a system or process
• Logical model


  A non-technical pictorial representation that depicts what a system is or does
• Physical model


  A technical pictorial representation that depicts what a system is or does and how the system is implemented
• Flowcharts


  • Visual representations of processes or workflows
  • Use standardized symbols and shapes to depict the sequence of steps, decisions, and actions involved in a process

  
• Start/End


  • Represent the beginning and end points of the process, usually depicted as ovals
• Process


  • Represent an action or operation performed within the process, usually depicted as rectangles
• Decision


  • Represent a branching point in the process where a decision is made, usually depicted as diamonds
• Input/Output


  • Represent input or output of data in the process, usually depicted as parallelograms
• Arrows


  • Show the flow of control or data between different steps or elements of the flowchart
• Data Flow Diagram (DFD)


  A graphical representation of the flow of data within a system

  
• External Entities


  • Sources or destinations of data outside the system being modeled
• Processes


  • Activities or functions that transform data inputs into data outputs within the system
• Data Flows


  • Represent the movement of data between the external entities, processes, and data stores in the system

  
• Data Stores


  • Represent where data is stored within the system
• Process Decomposition


  The act of breaking a system into sub-components
• Decomposition Diagram


  A visual representation used in system analysis and design to illustrate the hierarchical structure of a system or process

  
• Hierarchical Structure


  Decomposition diagrams show the hierarchical relationships between different components of the system

  
• Composite Data Flow


  A data flow that consists of multiple individual data flows
• Elementary Data Flow


  A single piece of data that moves between processes in a system
• CRUD


  Create, Read, Update, and Delete
• Data Structure


  The organization or arrangement of data attributes within a system
• Data Structure Attribute


  The smallest unit of data that has meaning to users and the business
• Data Type


  A class of data that can be stored in an attribute
• Domain


  A set of permissible values that a data element can hold
• Diverging Data Flows


  A data flow that splits into multiple data flows
• Converging Data Flows


  The merger of multiple data flows into a single packet
• When to Draw Process Models: Strategic systems planning, Business process redesign, Systems analysis