Development Methodologies

Waterfall Methodology

• The Waterfall Model is a sequential software development methodology that shifts through ['requirements', 'design', 'implementation', 'verification' and 'maintenance'] phases.
• Each phase results in a deliverable that feeds into the next phase.
• It assumes that requirements will remain stable after they are defined.
• It focuses on extensive documentation, which makes it easier for new team members to get up to speed.
• The drawback of the Waterfall methodology is that it does not reflect changes in requirements during the development process.

Agile Methodology

• The Agile Methodology emphasises close collaboration between the programming team and business stakeholders; real-time communication, rather than writing extensive requirements upfront; and breaking the product into a series of incremental releases.
• Agile methodologies allow for changing requirements over time by using time-boxed, iterative workflows known as sprints.
• Agile place emphasis on face-to-face communication over written documents when the team is all in the same location.
• It focuses on minimalistic method of doing just enough as necessary. (Just Enough Documentation).

Iterative and Incremental Development

• Iterative and Incremental development methodology allows changes in project development stages. After each stage, the project is put to test and changes are made accordingly.
• In Iterative and Incremental development methodology, development is segmented into small builds of the software where segments are divided on the basis of software functionality.
• The iterative approach allows development to be more flexible, while the incremental part of this methodology allows development teams to demonstrate progress in more quantifiable terms.

Spiral Model

• Spiral Model combines elements of both design and prototyping-in-stages, combining advantages of top-down and bottom-up concepts.
• Each phase in spiral model starts with a design goal and ends with a review meeting.
• Spiral Model involves risk analysis, and includes risk handling as a specific phase.
• It is a good choice for large and complex projects.

Rapid Application Development (RAD)

• RAD is suitable for projects where requirements are not clear and can be implemented in parallel.
• RAD phase includes planning, user design, construction, cutover.
• It is suitable when technical risks are less and high modularization is required.
• RAD has shorter development time and higher customer satisfaction.