The document discusses the waterfall model, which is an early software development life cycle approach where each phase must be completed before the next begins, with no overlapping phases. The phases include requirements, design, implementation, testing, and maintenance. The waterfall model works best for smaller, clearly-defined projects with stable requirements and is simple to understand and use. However, it does not allow for changing requirements and produces no working software until late in the cycle.

1. System Development Life Cycle (SDLC)
Waterfall Model
Presented By: Manar Alfarsi

2. Outline
 Waterfall Model Definition.
 Phases of Waterfall Model.
 When to use Waterfall Mode?
 Waterfall Model Advantages.
 Waterfall Model Disadvantages.

3.  Waterfall model is the earliest SDLC approach that was used
for software development .
 It is also referred to as a linear-sequential life cycle model.
 Each phase must be completed before the next phase can
begin.
 The outcome of one phase acts as the input for the next phase
sequentially.
 There is no overlapping in the phases.
Waterfall Model Definition

4. Phases of Waterfall Model

5. When to use Waterfall Model?
 Requirements are very well documented, clear and fixed.
 Product definition is stable.
 Technology is understood and is not dynamic.
 There are no ambiguous requirements.
 Ample resources with required expertise are available to
support the product.
 The project is short.

6. Advantages
 Simple and easy to understand and use.
 Each phase has specific deliverables and a review process.
 Phases are processed and completed one at a time.
 Works well for smaller projects where requirements are
very well understood.
 Clearly defined stages.
 Well understood milestones.
 Easy to arrange tasks.
 Process and results are well documented.

7. Disadvantage
 No working software is produced until late during the life
cycle.
 High amounts of risk and uncertainty.
 Not a good model for complex and object-oriented
projects.
 Poor model for long and ongoing projects.
 It is difficult to measure progress within stages.
 Cannot accommodate changing requirements.
 Adjusting scope during the life cycle can end a project.

8. References
 http://www.tutorialspoint.com/sdlc/sdlc_waterfall_m
odel.htm
 http://www.waterfall-model.com/