Wed - exam note

Exam Structure

  • 10 Multiple Choice
  • 5 Short Questions
  • 1 Compulsory Question (DFD)
  • 2 out of 3 Long Questions

Systems Development Lifecycle (SDLC) Phases

  • Project Planning: Initiate, ensure feasibility, plan schedule, obtain approval.
  • Analysis: Understand business needs and processing requirements.
  • Design: Define solution system based on requirements and analysis decisions.
  • Implementation: Construction, testing, user training, and installation.
  • Support: Keep system running and improve.

Data Flow Diagrams (DFD)

  • Graphical system model showing main requirements for an IS in one diagram.
    • Inputs/outputs
    • Processes
    • Data storage
  • Easy to read and understand with minimal training.

DFD Symbols

  • Process: Transforms inputs into outputs.
  • Data flow: Data moving between places.
  • External agent: Source or destination of data outside the system.
  • Data store: Data at rest for later use.
  • Real-time link: Communication between an external agent and a process.

DFD Levels of Abstraction

  • DFDs are decomposed into additional diagrams for multiple detail levels.
  • Higher-level diagrams: general views.
  • Lower-level diagrams: detailed views.
  • Context Diagrams:
    • Highest level (most abstract) view of system.
    • Shows system boundaries.

Testing

  • Unit Testing: Testing individual modules before integration.
  • Integration Testing: Tests behavior of a group of modules; tests normal processing and exceptions.
  • System Testing: Tests the entire system behavior.
    • Performance test: Checks time-based requirements.
    • Acceptance test: Determines whether system meets user requirements.

Implementation Alternatives

  • Variations on obtaining system
    *Facilities Management
    *Packaged Software/Turnkey/ERP
    *Custom-built software in-house
  • Selection Dimensions:
    • Buy vs. Build
    • In-house vs. Outsource

User Interface Design Guidelines

  • Visibility: All controls should be visible with immediate feedback.
  • Affordance: Appearance suggests functionality.
  • Use published interface design standards.

System Installation

  • Direct Installation:
    • New system installed and made operational quickly.
    • Advantage: simplicity.
    • Disadvantage: risk due to no backup.
  • Parallel Installation:
    • Old and new systems operate together.
    • Advantages: low risk, continuous backup.
    • Disadvantage: cost to operate both systems.