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Definition of User requirement specification (URS)

What is a user requirement specification

Clearly defined requirements are vital for project success, formalizing the client and provider agreement. Explore what should and should not be included in user requirement specifications (URS) in software engineering and system design.

What is a user requirements specification (URS)

A user requirement specification (URS) is a document that outlines a system's requirements from the end user's perspective. It serves as a formal document that captures and defines what users expect from a system, product, or service. The URS is a crucial step in the early stages of system development or project planning, as it provides a foundation for design, development, and testing.

What to include in a user requirement specification

Every successful project starts with a clear plan, and that's where a SRS comes in. This document lays the foundation for your project by outlining what the software needs to do, how it will work, and how it should perform.

The four key sections that make up a strong SRS are introduction, system and functional requirements, external interface requirements, and non-functional requirements.


It sets the stage for the entire project by providing a clear overview for everyone involved.

  • Project scope — Briefly describe the project's goals and boundaries. What are you building? What problem are you solving?
  • Product purpose — Define the core functionality and value proposition of your product. What will it do for users?
  • Target audience — Who are you building this product for? Understanding their needs and expectations is crucial.
  • Product usage — How will users interact with the product? This could include user interface details or workflow descriptions.

System and functional requirements

This section focuses on functionalities that enable the product to fulfill its purpose.

  • System features — List the core functionalities that make up your system. 
  • User needs — Link each feature back to specific user needs outlined in the introduction. Ensure they align smoothly.
  • Detailed requirements — Break down each feature into specific, measurable, achievable, relevant, and time-bound (SMART) requirements.

External interface requirements

It goes beyond the core system and focuses on how it interacts with the outside world.

  • External components — Identify all external elements your system interacts with, like user interfaces, hardware, or other software.
  • Communication protocols — Define how data is exchanged between your system and external components. Think of it like setting a common language.
  • Security measures — Specify any security requirements to protect data and ensure system integrity.

Non-functional requirements

NFRs tell us how the system will behave and perform, focusing on qualities beyond functionality. 

  • Performance standards — State expectations for speed, reliability, and scalability. How quickly should it respond?
  • Usability & accessibility — Describe the user interface and user experience, considering accessibility for all users.
  • Maintainability — Define how easy it will be to modify and update the system in the future.

By following this breakdown and tailoring it to your specific project, you can write a clear and comprehensive URS that sets the stage for a successful development process.

What does not go into a user requirement specification

A URS typically focuses on the definition of the functional and non-functional requirements of a system, emphasizing what the system should do or how it should perform. However, it does not typically include specific technical implementation details, coding specifics, or design intricacies. These details are usually part of other documents in the development process, such as a System design specification (SDS) or technical specification. Additionally, project management details, timelines, and resource allocations are usually kept separate in a project plan rather than being part of the URS. The URS is primarily concerned with the needs and expectations of the end-users and stakeholders, serving as a foundation for the subsequent stages of system development.

Key Takeaways

  • A user requirements specification (URS) is a user-centric planning document in software engineering. It defines system functionalities from the user's perspective, aiding designers and engineers. A clear and concise URS facilitates understanding, cost estimation, and timetable planning, ensuring alignment with client needs.
  • A comprehensive URS includes key sections such as introduction, system requirements and functional requirements, external interface requirements, non-functional requirements. Each section plays a specific role in defining and ensuring the success of the project.
  • The URS emphasizes functional and non-functional requirements but excludes technical implementation, coding, and design details. These are addressed in separate documents like SDS. Project management details are kept in a project plan, while the URS primarily focuses on user needs and expectations.