Waterfall model
- 2. What is Waterfall Model? • The waterfall model is a linear, sequential approach to the software development life cycle (SDLC) that is popular in software engineering and product development. The waterfall model emphasizes a logical progression of steps.
- 3. One should use the waterfall model only when: - Requirements are very clear and fixed. - There are no ambiguous requirements. - The project is short. - low budget projects.
- 4. History of Waterfall Model • Firstly presented by Herbert Benington in 1956. • Which was republished in 1983. • Winston Royes formally cited this as article in 1970. • But Royes did not mention Waterfall term in that. • ‘Waterfall’ term was first used by Bell in 1976. • The US dept. of Defense worked with this for software development in 1985 and stated the six phases of the model.
- 6. Advantages of waterfall model: • Good for small projects. • Clearly defined stages. • Easy to use and follow. • When you move to the next phase, you have a clear picture of previous phases. • Design errors are identified early,before any software is writte • Change is limited. • Stakeholders and customers are engaged regularly.
- 7. • Not useful for large project. • High amounts of risk and uncertainty. • Difficult to add or change requirements if they are identified and needed after the first phase. • There is a big problem if testing fails the software. • Can take a long time to deliver. Disadvantages of waterfall model:
- 8. Limitations of WaterFall model: • Does not show iteration in software life cycle. • Does not show overlap between phases. • Software requirements are tested late in life cycle. • Operational system available late in life cycle. • Does not support partial system development.