It provides a single reliable source of. Business requirements documents (brds) center on strategic objectives, business processes and user needs at a high level. A functional requirements document (frd)—also known as a functional requirements specification, functional specification, or functional specification document—is a more. According to the internet, a functional requirements document, abbreviated as frd, is a formal statement of an. Writing a functional requirements document (frd) is an essential step in the software development process.