A common comic mail circulates with this image, which gives good understanding of how requirements captured during a project life cycle goes like this: Typical Software Development Life-cycle explained Above picture succinctly tells about common perception of developing a software, how requirement understanding filters with changing roles, time and space with gaps between factual and results. Thanks to the the word "agility", which has evolved in world of software technology with the evolution of Rational unified process the term use-case or scenario development for documenting and capturing requirement in the initial phase of software development. "A use case is a software artifact of systems and process of expected sequence of interactions between a module and an external actor, which leads the actor to desired goals and objectives. " Use case scenarios can be mirrored as clip of a movie making scene development where-in director has assigned a s...