Functional Requirement


A functional requirement is a specific feature or capability that a system should possess in order to meet its intended purpose and satisfy its users’ needs. It defines the system’s interactions, inputs, processes, and outputs, detailing the behavior and functionality expected from a product, application, or software. Functional requirements are essential in guiding the design and development process to ensure the resulting system meets the desired objectives.


The phonetic pronunciation of “Functional Requirement” is:/fʌŋkʃənəl rɪˈkwaɪərmənt/- Functional: /fʌŋkʃənəl/- Requirement: /rɪˈkwaɪərmənt/

Key Takeaways

  1. Functional requirements define the system’s features, processes, and capabilities, outlining what the system is intended to accomplish.
  2. They are often described in terms of inputs, processes, and outputs, making them critical for establishing the system’s overall purpose and desired performance.
  3. Creating clear and comprehensive functional requirements helps ensure a successful project outcome by defining expectations, facilitating communication, and aiding in evaluation and testing.


The technology term “Functional Requirement” is important because it defines the specific, expected behavior of a system or software program and ensures that it meets its intended purpose effectively.

When developing or implementing new technology, clear and precise functional requirements help the developers, project managers, and stakeholders work together to create a cohesive system capable of achieving specific goals.

They establish measurable criteria for evaluating the system’s performance, facilitate smooth communication among team members, and, ultimately, contribute to successful project completion.

Additionally, well-defined functional requirements play a crucial role in determining the system’s usability, compatibility, and maintainability, reducing risks of misunderstandings or failures, and increasing overall user satisfaction.


Functional requirements play a crucial role in the development process of various systems, as they define the expected functions that a system must deliver to fulfill its desired purpose. These requirements translate the needs of users, customers, and other stakeholders into specific, testable characteristics that a system or product must satisfy. The primary objective of establishing functional requirements is to ensure that the developed system caters to the needs of its users, operates efficiently, and provides a seamless user experience.

By establishing clear and concise functional requirements, developers and designers can mitigate potential miscommunications and discrepancies between stakeholder expectations and the final output, leading to a robust, efficient, and user-friendly system. In order to achieve their intended purpose, functional requirements go beyond just listing the desired functions; they delve into the details of input, output, and processes required for each functionality. This includes aspects such as data handling, expected response times, user interface interactions, and other performance-related factors.

These requirements serve as a blueprint for development teams, guiding them through the design, implementation, and testing phases of a project. Upon completion, the functional requirements become a reference point for validating the system’s effectiveness in meeting user needs and expectations. In summary, functional requirements are a critical aspect of ensuring the successful development and deployment of a technology system tailored to satisfy its intended users.

Examples of Functional Requirement

Functional requirements define the desired operations or features of a system or software application. Here are three real-world examples of functional requirements in technology projects:

Online Banking System:In an online banking system, functional requirements may include: a. Account access and management – The system should provide secure access to user accounts, enable viewing of account balances and transaction history, and allow users to manage account settings. b. Fund transfers – The system should enable users to transfer funds between their own accounts or to third-party accounts within the same bank or other institutions. c. Bill payments – The system should facilitate the payment of utility bills, credit card dues, and other services directly from users’ accounts.

E-commerce Website:Functional requirements for an e-commerce website can involve: a. Product catalog – The website should display a searchable and organized catalog of available products with detailed descriptions, images, and pricing information. b. Shopping cart functionality – The website should allow users to add, remove, and modify items in their shopping cart, as well as view the cart’s contents and prices at any time. c. Secure checkout and payment – The website should facilitate a secure checkout process for users, with various payment options such as credit/debit cards, PayPal, and other third-party payment services.

Customer Relationship Management (CRM) Software:Examples of functional requirements in a CRM software include: a. Contact management – The CRM should allow users to store and manage customer information such as names, addresses, phone numbers, and email addresses. b. Task and event tracking – The CRM should enable users to create and track tasks, appointments, and events related to customer interactions, making it easier to keep track of important deadlines and follow-ups. c. Reporting and analytics – The CRM should provide customizable reports and analytical tools to help users identify patterns, trends, and opportunities in customer data, and use that information to make informed decisions and improve their overall sales and marketing strategies.

Functional Requirement FAQ

What is a functional requirement?

A functional requirement is a description of a specific feature or functionality a system must possess to meet its intended purpose. It defines what the system is supposed to do, such as the actions it must perform, the details of inputs and outputs, and the expected behavior in response to user actions or system events.

Why are functional requirements important?

Functional requirements are important because they communicate what the system is expected to do, allowing developers to build the system accurately and efficiently. They provide a shared understanding of the system’s functionality among stakeholders, including clients, developers, and testers. Additionally, functional requirements help guide the documentation, testing, and maintenance of the system throughout its lifecycle.

How do you write a functional requirement?

To write a functional requirement, follow these steps:
1. Identify the intended users and their needs.
2. List the required features or functionality in response to those needs.
3. Write clear, concise, and unambiguous statements for each identified feature or functionality.
4. Use appropriate terminology and language that can be understood by all stakeholders (clients, developers, and testers).
5. Prioritize the requirements, considering criticality, dependencies, and development effort.
6. Review and validate the requirements with stakeholders to ensure accuracy and completeness.

What are some examples of functional requirements?

Examples of functional requirements include:
1. The system shall allow users to create, read, update, and delete records in a database.
2. The application must support multiple languages such as English, Spanish, and French.
3. The software shall generate reports in various formats, including PDF and CSV.
4. A user authentication feature must be implemented to ensure only authorized users can access the system.
5. The website shall automatically adjust its layout and appearance for optimal viewing on devices of different screen sizes (responsive design).

What is the difference between functional and non-functional requirements?

Functional requirements describe what a system is supposed to do and define the features or functionality it must have to meet its intended purpose. Non-functional requirements, on the other hand, describe how well a system performs its functions and define the characteristics or qualities it must have, such as performance, usability, security, and scalability. Both functional and non-functional requirements are important in developing a complete and robust system.

Related Technology Terms

  • System Functionality
  • User Stories
  • Use Cases
  • Data Flow Diagrams
  • System Inputs and Outputs

Sources for More Information


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