5. software process model
- 2. SOFTWARE ENGINEERING Software process Model organizing a structured set of activities to develop software systems. The process model is a description of a software process. Model is an abstraction (summary) of the actual process. Process model may include activities which are part of software process, software product and role of people involved in software engineering.
- 3. SOFTWARE ENGINEERING Waterfall Model Simplest Model It states that the phases are organized in a linear order Feasibility Then Requirement analysis Design
- 4. SOFTWARE ENGINEERING Coding Testing Installation Linear ordering of activities has some important consequences, first to clearly identify the end of a phase and beginning of the other Certification mechanism
- 5. SOFTWARE ENGINEERING Intermediate Products So output of the project should be the complete software along with the documentation In waterfall model the output of first phase becomes the input of 2nd phase and cannot be changed
- 6. SOFTWARE ENGINEERING Assumptions For a successful project all phases listed in the model must be performed Any different ordering of the phases will result in a less successful software
- 7. SOFTWARE ENGINEERING Projects outputs in waterfall model Requirement analysis document Design Document Final code Test Plan Project plan Any manuals
- 9. SOFTWARE ENGINEERING Limitations of water Fall Model Premature Freezing Choosing of hardware No visibility
- 11. SOFTWARE ENGINEERING Prototyping The goal of this model is to counter the first two problems of waterfall model Before freezing of the requirements a throwaway prototype is built based on the currently known requirements .
- 12. SOFTWARE ENGINEERING By using the prototype the customer can get the actual feel of the system Good idea for complicated systems In such cases the client play with the prototype that provides other requirements of the systems
- 13. SOFTWARE ENGINEERING Cost issue Reduce testing Early visibility Fast cycle Crisp requirements Early testing
- 15. SOFTWARE ENGINEERING Incremental Model It tries to combine the benefits of both prototype and waterfall model It uses increments In each increment extension and design modification are made Testing is easy
- 16. SOFTWARE ENGINEERING Feed back to the client First increment contains the key aspects of the system Project Control list Visibility Useful when limited staff
- 19. SOFTWARE ENGINEERING RAD Model Rapid application development that emphasizes an extremely short development cycle Rapid development is achieved by using component based construction
- 20. SOFTWARE ENGINEERING Business modeling Data modeling Process Modeling Application generation Testing
- 21. SOFTWARE ENGINEERING Drawbacks Human resources Commitment Not suitable when technical risks are high
- 24. SOFTWARE ENGINEERING Spiral Model This model is mixture of all the models It provides the potential for rapid development in different increments In this, software is developed in a series of incremental releases The first increment may be a paper model or prototype
- 25. SOFTWARE ENGINEERING Customer Communication Planning Risk analysis Engineering Construction Customer evaluation