What is a Functional Requirements Document (FRD)?
December 22, 2025An 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. The FRD is produced by business analysts or sometimes the technical team in response to the business requirements (captured in a BRD – Business Requirements Document).
The key purpose of an FRD is to translate business needs into technological functions in a system. It’s where project stakeholders and the technical development team meet. The creation of the FRD facilitates and ensures collaboration between business and technical stakeholders:
- Business – it restates the business requirements in terms of functional features and capabilities to be supported by the new system or platform. This ensures the project team understands the business requirements and are on their way to implement a solution which addresses the business needs or problems.
- Technology – it captures key technical constraints and commitments as well key interfaces to external systems
While created by the solution team comprising business analysts, the FRD should be solution independent (in general) and it should express what the application should do and not how it should do it. The FRD should not commit the technical team to a specific design. It is for the technical team to develop the actual design and implementation tactics.
The Functional Requirements Document (FRD) is one of the most popular ways to express functional specifications and define the requirements and functional solutions.
Examples of functional requirements:
The following are some uncategorized examples of software requirements:
- The system should have the capability to store and retrieve employee information.
- A dashboard should be made available on demand with charts and tables (details to follow) depicting organizational statuses in real time.
- The system should integrate with AWS SageMaker endpoints to retrieve predictions made on user input data for loan categorization.
- All user interfaces should load in under 3 seconds, even under a load of 100 concurrent users.
- Website traffic to and from the server should be secured using a 256-bit SSL.
The need for a functional requirements document
While the list of requirements above may suffice on smaller projects, large software development needs a more steady and structured approach. The FRD is a derivative and expanded version of the business requirement document BRD.
Functional requirements capture the intended behavior of the system and hence are tailored to fit the project’s need. This behavior may be expressed as services, tasks or functions the system is required to perform. The functional requirements are designed for the readership of a general audience to understand the system. Business as well as technical stakeholders should comprehend the same details in the FRD. Hence, no technical knowledge is required to understand this document.
The Functional Requirements Document (FRD) serves the following purpose:
- Demonstrates that the application provides value in terms of the business objectives and business processes.
- Contains a complete set of requirements for the application. It leaves no room for anyone to assume anything which is not stated in the FRD.
- Is solution independent. The FRD is a statement of what the application is to do. The FRD does not instruct designs or implementation details to the technical team. Hence, references to the use of a specific technology is entirely inappropriate in an FRD. Technical implementation details are confined to a Technical Specification (TS) or the Software Requirements Specification (SRS).
Types of functional requirements
Functional requirements are classified in a variety of ways. Commonly these are broken down in to functions as such:
- User authentication into the system
- Access authorization levels
- User interfaces
- Compliance to laws or regulations features
- Database transactions processing
- APIs for systems integration
- Report generation and visualization
- Business / organization specific logic
Functional requirements document FRD sections
Both functional and nonfunctional requirements can be formalized in the Functional Requirements Document. FRD / FRS’s contain descriptions of features, functions and abilities that the software product must provide. The document also defines constraints and assumptions. These can be a single document communicating functional requirements or it may accompany other software documentation like user stories and use cases.
The FRD is created for the entire solution or a part of it, and is usually an iterative process of consultations with business and technical stakeholders. Every feature must be documented before actually developing it. It is not uncommon for the FRD to undergo a series of revisions as the product is developed over multiple releases. This is because as newer information and client feedback is received, the development team gains greater clarity of the objectives. Everyone understands the importance of features, which can be accordingly prioritized.
The FRD / FRS includes all or part of the following sections:
- Introduction
1.1 Purpose of Document
1.2 Project Summary
1.3 Background
1.4 Project Scope
1.5 System Purpose
1.5.1 Users
1.5.2 Location
1.5.3 Responsibilities
1.5.4 Need
1.6 Overview of Document - Functional Objectives
2.1 High Priority
2.2 Medium Priority
2.3 Low Priority - Non-Functional Objectives
3.1 Reliability
3.2 Usability
3.3 Performance
3.4 Security
3.5 Supportability
3.6 Online user Documentation and Help
3.7 Purchased Components
3.8 Interfaces - The Context Model
4.1 Goal Statement
4.2 Context Diagram
4.3 System Externals - The Use Case Model
5.1 System Use Case Diagram
5.2 Use Case Descriptions (for selected cases) - User Stories
- Appendix
Glossary
This list of sections is meant to be representative and a guide, not a hard and fast rule. Every project is different, and you will need to determine the level of detail required for your FRD.
