Functional Requirements

The Functional Requirements Specification documents the operations and activities that a system must be able to perform.

Functional Requirements should include:

The Functional Requirements Specification is designed to be read by a general audience. Readers should understand the system, but no particular technical knowledge should be required to understand the document.

Examples of Functional Requirements

Functional requirements should include functions performed by specific screens, outlines of work-flows performed by the system, and other business or compliance requirements the system must meet. Download an example functional requirements specification or use these quick examples below.

Interface requirements

Business Requirements

Regulatory/Compliance Requirements

Security Requirements

Depending on the system being described, different categories of requirements are appropriate. System Owners, Key End-Users, Developers, Engineers, and Quality Assurance should all participate in the requirement gathering process, as appropriate to the system.

Requirements outlined in the Functional Requirements Specification are usually tested in the Operational Qualification.

Additional Comments

The Functional Requirements Specification describes what the system must do; how the system does it is described in the Design Specification.

If a User Requirement Specification was written, all requirements outlined in the User Requirement Specification should be addressed in the Functional Requirements Specification.

The Functional Requirements Specification should be signed by the System Owner and Quality Assurance. If key end-users, developers, or engineers were involved with developing the requirements, it may be appropriate to have them sign and approve the document as well.

Depending on the size and complexity of the program, the Functional Requirements Specification document can be combined with either the user requirements specification or the design specification.

Frequently Asked Questions about Functional Requirements

Q: What is the difference between a User Requirement Specification and the Functional Requirement Specification?
A: User Requirements describe the end-user requirements for a system. Functional Requirements describe what the system must do.

Q: Can I see an example of a functional specification?
A: We have a sample functional specification for an Excel spreadsheet available for download.

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Alternative Document Names and Acronyms

The following terms or abbreviations are sometimes used: Functional Requirement Specification, Functional Specification, Program Specification, Functional Specs, Functional Spec, FRS, FS. These documents generally serve the same purpose.

Validation Document Resources