The given BRD specifications are analyzed in detail from the software system point of view. Based on the analysis, the deliverable document is referred to as a Functional Specification Document (FSD). FSD is more of a technical response against the given BRD. In our case, let us define one of the FSD entries as, when the end user clicks the sign up button, the application routes to the new user registration form. So, FSD describes the interaction between human and enterprise application, that is, the end user and mobile application.