The software development life cycle is initiated by the client needs.
In the beginning, these needs are in the mind of the client.
The software developer by using a software development model has to identify, discover, understand and fulfill the requirement of the client in order to satisfy the client.
The requirement phase of the Software Development Life Cycle translates the idea in the mind of the client into a formal document known as Software Requirement Specification (SRS).
The quality of the SRS impacts client satisfaction, system validation, quality of final software, software development cost and schedule. A high quality SRS is necessary to produce the high quality software.
A developer fails to satisfy the client because of the three reasons