Waterfall Model definition programming
A software life-cycle
or product life-cycle model, described by W. W. Royce in 1970, in which development is supposed to proceed linearly through the phases of requirements analysis
, design, implementation, testing (validation), integration and maintenance. The Waterfall Model is considered old-fashioned or simplistic by proponents of object-oriented design
which often uses the spiral model
Earlier phases are sometimes called "upstream" and later ones "downstream".
Compare: iterative model.
[W. W. Royce, "Managing the Development of Large Software Systems", Proceedings of IEEE WESCON, August 1970].