Properties of requirements specifications: Only specifies external system behavior. Specifies constraints on the implementation. Allows provisions for easy modification. Serves as a reference document for system development and maintenance. Records possible forethought on life cycle of the system. Characterizes acceptable responses to undesired inputs and events of failure.
Requirements specification document structure: Overview of system goal and objectives. Operating and development environments and platforms. External interfaces and data flow. Functional requirements. Performance requirements (that may constrain functionality). Exception handling. Implementation priorities. Foreseeable modifications. Design suggestions.
Replaced/Superseded by document(s)
Before you can design a solution, it is important to understand what the problem entails and what you are supposed to accomplish. Begin with a statement of the goal for the project. The goal can be further broken down into a list of objectives to be achieved. Using this as your target, set the milestones and delivery/release date accordingly.