Evolutionary Software Process Model

There is growing recognition that software such as all complex systems evolves over a period of time. Business and product requirements often change as development proceeds or changes, making a straight line way to an end product unrealistic tight market deadlines make completion of a comprehensive software product impossible but a limited edition must be introduced to meet competitive or business pressure as a set of core product or system requirements is well understood but the details of system extensions or product have yet to be describe.  In these and same situations software engineers require a process model that has been explicitly designed to accommodate a product that evolves over time.

The linear sequential model is designed for straight line development. In essence the waterfall approach assumes that a complete system will be delivered after the linear sequence is completed. The Evolutionary models are called iterative. They are characterized in a manner that enables software engineers to build increasingly more complete edition of the software.