Waterfall

In Project Management the Waterfall methodology is a sequential design process, often used in software development processes in which progress is seen as flowing steadily downwards (like a waterfall) through the phases of Conception, Initiation, Analysis, Design, Construction, Testing, Production/Implementation and Maintenance.

Waterfall, as a project management methodology, has been criticized for not being able to cope with constant changes in software projects, and with the inability of customers to specify adequate requirements before they have tried prototypes. Also, the huge overhead of specifying requirements before starting the actual development may cause long delays of a project. The iterative nature of agile makes it an excellent alternative when it comes to managing development projects, especially software projects