The waterfall model is a linear, sequential approach to the software development life cycle (SDLC) that is popular in?software engineering?and?product development. The waterfall model emphasizes?a logical?progression of steps. Similar to the direction water flows over the edge of a cliff, distinct endpoints or goals are set for each phase of development and cannot be revisited after completion. The term was first introduced in a paper published in 1970 by Dr. Winston W. Royce and continues to be used in applications of industrial design.
The waterfall methodology is composed of seven non-overlapping stages:
- Requirements: Potential requirements, deadlines?and?guidelines for the project are analyzed and placed into a?functional specification.?This stage handles the defining and planning of the project without mentioning specific processes.
- Analysis: The system specifications are analyzed to generate product models and?business?logic???that?will guide production. This is also when financial and technical resources are audited for feasibility.
- Design:?A design specification document is created to outline technical design requirements such as programming language,?hardware, data sources, architecture and services.
- Coding/Implementation: The?source?code?is?developed using the models, logic?and?requirements designated in the prior stages. Typically, the system is designed in smaller components, or units, before being implemented together.
- Testing: This is when?quality assurance,?unit,??system???and??beta?tests take place to report issues that may need to be resolved. This may cause a forced repeat of the coding stage for?debugging. If the system passes the tests, the waterfall continues forward.
- Operation/Deployment: The product or application is deemed fully functional and is deployed to a live environment.
- Maintenance: Corrective, adaptive and perfective maintenance is carried out indefinitely to improve, update and enhance the final product. This could include releasing??patch???updates?or releasing new versions.
