Functional specification is one of the lengthy and important deliverable in project planning it covers many aspects of the project. Project objectives, business goals, requirement, functionality, interface, process flows, hardware and software requirements are the important part of functional specifications. Development of functional specification comes under project manager belt and in order to cover the detail aspects he get help from project team members. After completing the functional specification it’s sent to the client organization for signoff, Signature on FS means customer is agreed upon all the functionalities mention in the document. If anything requested by the client which is not part of the functional specification it will consider as change requirement.