The Software Development Life Cycle
Before delving into the descriptions for each of the methodologies, it is important to understand the context of the problem that these process definitions are intended to solve. The software development life cycle (SDLC) is a standard definition of the phases involved in any software development project. Each methodology uses its own vocabulary to describe the following phases, but they are all consistent in purpose:
Concept Phase: The concept phase is used to initially evaluate the size and scope of a potential software development task or project. This phase usually entails the definition of the problem the software product is to solve and the criteria for how to determine the success of the delivery.