6/8/25About 259 words
The Waterfall Model
- It is an example of plan-driven process.
Phases
- Requirements Analysis and Definition
- Establish services, constraints, and goals by consultation with system users.
- Defined in detail.
- Serve as a system specification.
- System and Software Design
- Allocate the requirements to either hardware or software system by establishing an overall system architecture.
- Identifying and describing the fundamental software system abstractions and their relationships.
- Implementation and Unit Testing
- Software design is realized as a set of programs of program units.
- Unit testing involves verifying that each unit meets its specification.
- Integration and System Testing
- The individual program units or programs are integrated and tested as a complete system.
- After testing, the software system is delivered to the customer.
- Operation and Maintenance
- The system is installed and put into practical use.
- Maintenance involves correcting errors which were not discovered in earlier stages.
Problems
- It is difficult to make any change during the development process. In principle, a phase has to be done before moving onto the next phase.
- Inflexible partitioning of the project into distinct stages makes it difficult to respond to changing customer requirements.
- The waterfall model is mostly used for large system engineering projects, where a system is developed at several sites.