The functional requirements document (frd) is a formal statement of a product's functional requirements. An frd or functional requirements document serves as a contract for formal statement, between the business stakeholders and the technology team, on an application’s functional requirements. Documenting the functional requirements provides several important benefits to the organisation and to the process of developing a solution. Business requirements documents (brds) center on strategic objectives, business processes and user needs at a high level. A user requirements document, written by the product manager, is centered around the end user’s needs and expectations for a product.it translates user requirements into.