Software Engineering: Topic: Waterfall Model
- 1. Software Engineering Waterfall model Prof. Navya Francis Asst. Professor Kristu Jayanti College
- 2. Software Development Life Cycle (SDLC)
- 3. 1. Waterfall Model 2. Prototype Model 3. Rapid application development Model 4. Evolutionary Model 5. Incremental Model 6. Iterative Model 7. Component based software engineering 8. Spiral Model Process Models
- 5. WATERFALL MODEL The Waterfall Model was the first Process Model to be introduced. It was developed by Royce, 1970 It is also referred to as a linear-sequential life cycle model or software life cycle. It is very simple to understand and use. In a waterfall model, each phase must be completed before the next phase can begin and there is no overlapping in the phases.
- 7. 1. REQUIREMENTS ANALYSIS AND DEFINITION • The system’s services, constraints and goals are established by consultation with system users. • They are then defined in detail and serve as a system specification.
- 8. 2. SYSTEM AND SOFTWARE DESIGN The systems design process partitions the requirements to either hardware or software systems. It establishes an overall system architecture. Software design involves identifying and describing the fundamental software system abstractions and their relationships
- 9. 3. IMPLEMENTATION AND UNIT TESTING During this stage, the software design is realised as a set of programs or program units. Unit testing involves verifying that each unit meets its specification.
- 10. 4. INTEGRATION AND SYSTEM TESTING The individual program units or programs are integrated and tested as a complete system to ensure that the software requirements have been met. After testing, the software system is delivered to the customer.
- 11. 5. OPERATION AND MAINTENANCE Normally (although not necessarily) this is the longest life-cycle phase. The system is installed and put into practical use. Maintenance involves correcting errors which were not discovered in earlier stages of the life cycle, improving the implementation of system units and enhancing the system’s services as new requirements are discovered.
- 12. Advantages of Waterfall Model ADVANTAGES ADVANTAGES • Easy to understand and implement. • Widely used and known. • Identifies deliverables and milestones. • It redeems the software development process of the code and fix problems. • Main strength lies in the fact that it emphasizes the software development process must be planned and well managed. • It allows for communication between the customer and developer and specifies what will be delivered.
- 13. Disadvantages of Waterfall Model DISADVANTAGES • Cannot accommodate changing requirements. • Model is rigid • High amounts of risk and uncertainty. • Huge gap in-between phases and there is no way to cross check user requirements. • Not a good model for complex and object-oriented projects. • Adjusting scope during the life cycle can end a project.
- 14. Where to use waterfall model? When to use WATERFALL MODEL • Requirements are very well known, clear and fixed. • Product definition is stable. • Technology is understood. • There are no ambiguous requirements. • Ample resources with required expertise are available. • The project is small
- 15. THANK YOU