Alternative development approaches

• Waterfall method


  1. Requirements analysis

  2. Design

  3. Implementation

  4. Testing

  5. Operation

  6. Maintenance
• Waterfall method


  • Development consists of a sequence of stages, each of which must be completed before the next one commences
  • A deliverable is produced at the end of each stage
  • An earlier stage may have to be reworked if an error from development is discovered at a later stage.
  • ADV~ Well documented making maintenance easier, it is the industry standard for systems development
  • DISAV~Role or the end user is limited, can take a long time to develop
• Rapid Application Development (RAD)


  1. Business Modeling

  2. Data Modeling

  3. Process Modeling

  4. Application Generation

  5. Testing and Turnover
• RAD


  • A cyclical process with prototypes developed and evaluated by users
  • Strict deadlines with essential and non-essential requirements
  • Incremental development with additional functionality added in stages.
  • ADV~Reduction in development time, user feedback is encouraged.
  • DISADV~not suited to all system development, expensive
• Agile approach


  1. Design

  2. Develop

  3. Test

  4. Deploy

  5. Review

  6. Repeat
• Agile approach


  • System is split into iterations, each developed concurrently by a group of collaborators
  • A leader supervises the work of all groups.
  • ADV~Increased customer satisfaction due to fast delivery, system is regularly adapted to meet changing UR.
  • DISADV~Limited documentation making maintenance harder, only suitable for experienced programmers
• The end user is involved through the development in the agile approach as they are consulted by each group of collaborators via workshops