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1.2 Waterfall model.pptx

  2. Process Models: The Waterfall Model
  3. Software Process When you work to build a product or a system, it’s important to go through a series of predictable steps - a roadmap that helps you to create a timely, high-quality result. The roadmap that you follow is called a “software process”.
  4. Process model A process is defined as a collection of work activities, actions and tasks that are performed when some work product is to be created. Each of these activities, actions, and tasks reside within a framework or model that defines their relationship with the process and with one another.
  5. Types of Software Process Models • The Waterfall model • The Incremental model • Evolutionary process models: • Prototyping model • The spiral model • Concurrent process model
  6. Characteristics of Waterfall Model • Called as classic life cycle model. • This Model suggests a systematic, sequential approach to software development. • Software is developed as a whole. • Used when requirements are well understood in the beginning.
  7. Steps in Waterfall Model 1. Communication 2. Planning 3. Modeling 4. Construction 5. Deployment
  8. Waterfall Model & The V-Model
  9. Contd.. A variation in the representation of waterfall model is called the V- model. V-model depicts the assurance actions to the actions associated with communication, modeling and early construction activities. Once code has been generated, the team moves up the right side of V, essentially performing a series of tests that validate each of the models created as the team moved down left side. In reality, the is no difference between the waterfall and the V- model. The V- model illustrates how verification and validation actions are associated with earlier engineering actions.
  10. Advantages • Classic life cycle model • Useful in situations where requirements are fixed and proceed to completion in linear manner
  11. Disadvantages • There are also some disadvantages of waterfall model: Real projects rarely follow the sequential flow since they are always iterative. The model requires requirements to be explicitly spelled out in the beginning, which is often difficult. The customer must have patience. A working model is not available until late in the project time plan. Leads to ‘Blocking States’.
  12. Applications We can take real life examples for water fall model like automobile companies - When they are building a car, the requirements are fixed, predefined. There will be no change in the requirements during the process of building a car. Once we complete a stage, we proceed to the next one.
  13. MIND MAP
  14. SUMMARY Software Process Models  Waterfall Model  Communication  Planning  Modeling  Construction  Deployment  The V-Model • Advantages • Disadvantages • Applications
  15. Stimulating Question • Waterfall model is the most widely used process model than incremental process model- Justify your answer. ANS: • Real projects rarely follow the sequential flow since they are always iterative. • Compared to waterfall, iterative development allows flexibility in accommodating new requirements or changes thereof. It also provides room for improvement in succeeding iterations based on lessons learned from previous iterations.