Methodologies

Methodologies

1. Waterfall

   • Each stage follows the order given to it in the design stage.
     • Can only move onto the next stage once the current one is complete.
       • This makes it unrealistic as it assumes no mistakes occur in the production process.

2. Agile

   • Collection of different software development methods
   • Designed to cope with evolving project requirements and solutions.

3. Rapid application development

   • Involves producing successive prototypes
     • A prototype is made then shown to the end user
       • They then decide what needs to be changed or added to the prototype
         • The comments are then acted upon and a new prototype made
           • This process is continued until a prototype is made that meets the customers requitements
         • Allows for flexibility
           • However, the customer may keep changing their mind
             • So the development process continues for a long time
   • is a iterative cycle
     • Each cycle lasts about two to three weeks

4. Spiral

   • Similar to waterfall but has a greater focus on risk analysis
     • Makes it suitable for mission critical projects
   • Has good documentation control
     • makes maintaining the system easier
   • Disadvantages
     • Can be very costly
     • Risk analysis requires high experteis
       • Project's success relies heavily on this stage
     • Not suitable for smaller projects
   • Advantages
     • Software produced early in the software life cycle
     • Additional functionality can be added at later dates
   • When should spiral be used?
     • When cost and risk evaluation is important
     • For medium to long length projects
     • When there are potential changes to economic priorities
     • Users are unsure of needs
     • Requirements are complex
     • New product line
     • Significant changes are expected

5. Extreme programming

   • Focused on programming
     • Often leads to a poorly documented solution
       • Makes maintaining the program harder
   • Heavily user involved
   • Encourages pair programming
     • Two developers work on a workstation
       • One is the driver and the other the navigaior
         • The Driver writs the code while the navigator checks it and decided which direction to take the code in
           • Roles are swapped regularly
     • Makes the project more flexible
   • Advantages
     • Less dependent on individuals
     • Robust solutions
     • Solutions meet the needs of the end user
   • Disadvantages
     • No quality assurance of code
     • Requires constant end user involvement