The functional requirements document (frd) is a formal statement of a product's functional requirements. It allows you to apply a ratings system to your requirements, so you have the visibility (into the value, status, and description of each requirement) that’s. To help you upsurge towards your business goals, we suggest you to try using a business requirements document. Assumptions are future situations beyond the control of the project,. A functional specification document (fsd), also known as a functional requirements document (frd), is considered by many project management and software.