A functional specification document (fsd), also known as a functional requirements document (frd), is considered by many project management and software. According to the internet, a functional requirements document, abbreviated as frd, is a formal statement of an. They communicate what problem needs. Documenting the functional requirements provides several important benefits to the organisation and to the process of developing a solution. [provide a list of contractual or task level assumptions and/or constraints that are preconditions to preparation of the frd.