The software requirements specification is the single most important document in the software development process. It provides the basis for development as well as for validation. The SRS needs to include adequate definition of all requirements without specifying implementation or project management issues. The SRS should be completed early in the development process. However, it is very likely that changes will occur during the development life cycle. This is not an excuse for approving and releasing the current version of the SRS. When changes occur, the SRS must be revised. In any case, the concept is to deal with the current, approved version of the SRS. Ultimately, the SRS should include all the information needed to proceed into the design phase of software development.