The Functional Requirements Document (FRD) is a formal statement of an application’s functional requirements. When clearly defined, requirements lead to successful project outcomes. Approved requirements establish an agreement between the customer (internal or external) and a provider to reach the same goal. In this article, we explain the need for a functional requirements document, its structure, contents, and offer a sample template format for your work.
What is a Functional Requirements Document (FRD)?
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. 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.
Functional Requirements Document FRD Template
Click the button to download the example FRD template format for your work.
What are requirements in software development?
The Business Analysis Body of Knowledge (BABOK) acknowledges requirements as a usable representation of a need. Unambiguous, and detailed requirements help reduce cost and schedule risks and keeps the project on track.
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).
Functional Requirements Document FRD Template
Click the button to download the example FRD template format for your work.
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 / specification FRS template 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.
Sections
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. For free support with your FRD, use the chat box to chat with our support team or send an email to support@savioglobal.com.
Excel as a Business Analyst by experiencing all aspects of the role first hand
Join the Business Analyst Work Experience program
-
Business Analyst Work Experience Certification Course ProgramProduct on sale₹39,999
Explore other work experience programs
Functional Requirements Document FRD Template
Click the button to download the example FRD template format for your work.
Use Cases Model and Use Cases
Use cases describe the interaction between the system and external users that leads to achieving particular goals.
Each use case includes three main elements:
- Actors: These are the external users that interact with the system.
- System: The system is described as functional requirements that define an intended behavior of the product.
- Goals: The purposes of the interaction between the users and the system are outlined as goals.
There are two formats to represent use cases:
- Use case description
- Use case model (diagram)
A use case specification represents the sequence of events along with other information that relates to this use case. A typical use case specification template includes the following information:
- Use Case Name
- Summary
- Basic Flow
- Alternative Flows
- Extension Points
- Preconditions
- Postconditions
- Business Rules
A use case diagram doesn’t contain a lot of details. It shows a high-level overview of the relationships between actors, different use cases, and the system.
The use case diagram includes the following main elements:
- Use cases. Usually drawn with ovals, use cases represent different interaction scenarios that actors might have with the system (log in, make a purchase, view items, etc.).
- System boundaries. Boundaries are outlined as boxes that groups various use cases in a system.
- Actors. These are the figures that depict external users (people or systems) that interact with the system.
- Associations. Associations are drawn with lines showing different types of relationships between actors and use cases.
Example:
User Stories – What are they, and the need for it
The Agile Alliance describes user stories as work that is divided up into functional increments. User stories are developed and represented in a format that emphasizes the value to the end user of the system. A typical user story describes three components:
- The end goal for the user to use the system. This is the most important factor when it comes to developing functional requirements. Always begin with the end in mind; the value being delivered to the user. For example, the ability to order products (ecommerce like Amazon), track deliveries (ecommerce like Flipkart, Alibaba), enjoy relevant content (streaming like Netflix, Spotify, Zee or social media like Instagram, TikTok), interact with people (messaging or social media apps like Twitter, Facebook, Whatsapp), etc.
- The action that the user intends to perform, which when performed will lead to the goals being achieved (point #1). For example, placing an order, making payments, reviewing products, navigating pages, etc.
- The user role or type of user. For example, user roles may be customers, prospects, administrative users, etc.
Format of a user story
User stories are modelled on the following lines:
As a (role) I want to do (something) so that I can (benefit).
INVEST in a good user story
INVEST in an acronym that serves as a guideline for us to generate clear and useful user stories, and functional requirements in general.
The INVEST for a good user story stands for:
- “I” – Independent (of all other user stories)
- “N” – Negotiable (not a specific contract for features; the user story can be modified without much ado)
- “V” – Valuable (its creation should add value to the user)
- “E” – Estimable (to a good approximation)
- “S” – Small or Size Appropriate (so as to fit within an iteration or sprint)
- “T” – Testable (the user story should create something tangible that can be tested / verified, even if there isn’t a test for it yet)
- The INVEST checklist for evaluating user stories originated in Bill Wake’s 2003 article, which also utilized acronym SMART (Specific, Measurable, Achievable, Relevant, Time-boxed) for deliverables resulting from the decomposition of user stories.
- The INVEST acronym was one among the techniques recommended in Mike Cohn’s “User Stories applied“, which discusses the concept at length in Chapter 2.
Difference between functional and nonfunctional requirements
Functional requirements are product features or functions that developers must implement to enable users to accomplish their tasks. So, it’s important to make them clear both for the development team and the stakeholders. Generally, functional requirements describe system behavior under specific conditions. For example, the system should:
- Authentic a user login attempt after the user enters personal information.
- Feature a search box which allows users to discover products related to their search inputs among various products on the platform.
- Send a order confirmation email when a new order is placed upon successful payment.
Non-functional requirements in an FRD
Nonfunctional requirements define how the system should perform. Some examples are:
- The website pages should load in 3 seconds with up to 1000 concurrent users.
- The system should be able to handle 1 million users in a month without performance deterioration.
Here’s a brief comparison and then we’ll proceed to a more in-depth explanation of each group.
| Parameter | Functional requirements | Nonfunctional requirements |
|---|---|---|
| Objective | Describe what the product does | Describe how the product works |
| End result | Define product features | Define product properties |
| Focus | User requirements | User expectations |
| Documentation | Captured in use case | Captured as a quality attribute |
| Essentiality | They are mandatory | They are not mandatory, but desirable |
| Origin type | Usually user defined | Usually developer defined or other tech experts |
| Testing Precedence | Tested before nonfunctional testing | Tested after functional testing. |
| Examples | – User interface, – authentication, – authorization levels, – business rules, etc. | – Performance, – usability, – security – testing, etc. |
Functional Requirements Document FRD Template
Click the button to download the example FRD template format for your work.
Non-functional requirements detailed examples
Nonfunctional requirements describe how a system must behave and establish constraints of its functionality. The following are the most typical nonfunctional requirements utilized in most functional requirements documents FRD.
Usability
Usability defines how difficult it will be for a user to learn and operate the system. Here’s how usability can be evaluated:
- Efficiency of use: the average time it takes to accomplish a user’s goals, how many tasks a user can complete without any help, the number of transactions completed without errors, etc.
- Intuitiveness: how simple it is to understand the interface, buttons, headings, etc.
- Low perceived workload: how many attempts users need to accomplish a particular task.
Example: Usability requirements can consider language barriers and localization tasks: People with no understanding of French must be able to use the product. Or you may set accessibility requirements: Keyboard users who navigate a website using <tab>, must be able to reach the “Add to cart” button from a product page within 15 <tab> clicks.
Security
Security requirements ensure that the software is protected from unauthorized access to the system and its stored data. It considers different levels of authorization and authentication across different users roles. For instance, data privacy is a security characteristic that describes who can create, see, copy, change, or delete information. Security also includes protection against viruses and malware attacks.
Example: Access permissions for the particular system information may only be changed by the system’s data administrator.
Reliability
Reliability defines how likely it is for the software to work without failure for a given period of time. It decreases because of bugs in the code, hardware failures, or problems with other system components. To measure software reliability, you can count the percentage of operations that are completed correctly or track the average period of time the system runs before failing.
Example: The database update process must roll back all related updates when any update fails.
Performance
Performance is a quality attribute that describes the responsiveness of the system to various user interactions with it. Poor performance leads to negative user experience. It also jeopardizes system safety when it’s overloaded.
Example: The front-page load time must be no more than 2 seconds for users that access the website using an LTE mobile connection.
Availability
Availability is gauged in terms of time that the system’s functionality and services are available for use with all operations. So, scheduled maintenance periods directly influence this parameter. And it’s important to define how the impact of maintenance can be minimized. When writing the availability requirements, the team has to define the most critical components of the system that must be available at all times. You should also prepare user notifications in case the system or one of its parts becomes unavailable.
Example: New module deployment mustn’t impact front page, product pages, and check out pages availability and mustn’t take longer than one hour. The rest of the pages that may experience problems must display a notification with a timer showing when the system is going to be up again.
Scalability
Scalability requirements describe how the system must grow without negative influence on its performance. This means serving more users, processing more data, and doing more transactions. Scalability has both hardware and software implications. For instance, you can add memory, servers, or disk space to increase scalability. On the other hand, you can compress data, use optimizing algorithms, etc.
Example: The website attendance limit must be scalable enough to support 200,000 users at a time.
Functional Requirements Document FRD Template
Click the button to download the example FRD template format for your work.
You have the FRD. Now gain real and complete experiences as a business analyst. Join the Business Analyst Work Experience Program
-
Business Analyst Work Experience Certification Course ProgramProduct on sale₹39,999
Software prototypes and wireframes
Prototypes are meant to be inexpensive and quickly developed visual representations of requirements. Wireframes are low-detail illustrations of a website or an app. To break it down, wireframes are low-fidelity, basic layout and structural guidelines of your web product’s layout and prototypes are an advanced wireframe with more visual detail and interaction.
Wireframes serve as the foundation of a website or app’s visual layout, and it is at this stage that you will arrange elements on the page or screen. The purpose is to map out the priority of the content on the screen. A good rule of thumb is to keep your wireframes simple, with details that represent the core structure of your site / app only.
Best practices while creating the functional requirements document FRD
Creating documentation is an integral part of any software development project. Well-documented requirements ensure that stakeholders and developers are on the same page and also help define project scope and budget. Here are a few useful tips on how to make great documentation.
Requirements have to be clear and understandable. Make sure your requirements are stated in a concise manner that doesn’t contain ambiguity or allow different interpretations. Also, try to avoid technological jargon. Remember that each audience is different and stakeholders might not be familiar with specialized tech terminology. Instead, enrich your documents with visuals, diagrams, and graphs to support the information and make it easier to perceive. Adding glossaries and cross-links is also helpful.
Requirements have to be specific, accurate, and complete. When writing your documentation, be consistent with the language and make sure that your requirements are accurate. They should cover every scenario, but never contradict each other. Avoid vagueness and weak phrases such as “system has to be fast” or “when something happens.” Be specific and quantify the terms so that all the readers can understand them in the same way.
Requirements have to be testable. Write requirements in such a way that after the product is created, testing can show whether they are delivered successfully. The FRD is frequently used as a bases for user acceptance test case development and testing.
Requirements have to be feasible and sensible. Focus on the functionality and quality attributes that users actually need. Remember that requirements have to reflect higher-level business objectives.
Gain real and complete experience as a business analyst. Join the Business Analyst Work Experience Program
-
Business Analyst Work Experience Certification Course ProgramProduct on sale₹39,999
Frequently Asked Questions about the Functional Requirements Documents (FRD)
Who creates the functional requirements documents (FRD)?
The business analyst (BA) usually is the one who creates the FRD. The BA is best suited to propose a functional solution because of their deep understanding of the domain and the business needs.
When is the functional requirements documents (FRD) created?
The development of the functional requirements document (FRD) generally occurs after the finalization of the business requirements in the form of the BRD.
What is the use of the functional requirements documents (FRD) for downstream processes?
The FRD serves as a basis for all subsequent project development activities including the development of detailed system designs, technical specifications, and SIT and UAT test cases.
How can the functional requirements documents (FRD) be used in software testing?
The development of test cases primarily relies on the FRD as the best source of information. This is applicable for system integration testing (SIT) and user acceptance testing (UAT). Expected behaviors of the system, along with impact implications are derived from the FRD.
