Software Requirements Specification

Great !! You’ve got an idea for the next world-changing software product. But how are you going to explain it to people who are actually going to build it for you? How can you make sure the software that is built for you is actually fulfilling all your requirements? That’s right, you should describe your requirements in a formal document, its called Software Requirements Specification document.

This article covers what is SRS, why you need it, what are the essential points to be considered while creating an SRS document and how relevant or irrelevant it is in today Agile world.

SRS – What you should know about it

What is an SRS by the way?

A software requirements specification document primarily provides a description of a software product to be developed covering its functional and non-functional requirements. It acts as a formal agreement between the stakeholders and the development team of what to expect from the software product once it is developed.

A good SRS outlines how the Software System will work together with all internal components, hardware, synchronization with other programs and end-user interactions with a variety of real-life states.

To build a clear, brief, and easy to follow SRS, you must comprehend the details of the project. But then again, you must also understand SRS guidelines. Build SRS step-by-step by studying requirements. Not everyone in the team will have the same understanding level when you have a meeting and discuss a project.

To avoid any last-minute surprises, you may have to define the goals and technical objectives of the project clearly and concisely in a language that can be understood by everyone. There are a few things programmers must make every effort to incorporate in their SRS document to make it well-informed for a clean development project.

Why is an SRS important?

• It is used during review sessions.
• It serves a basis for the covenant between the customer and the developer.
• It serves as a resource for reference during any point of the development process.
• SRS document provides a clear insight into the end product to the client and the team during the initial phase.
• The looked-for objectives are differentiated in that way; the efforts of the developers concerning time and cost is considerably reduced.
• The objectives and the purposes, in addition to the anticipated outcomes, are appropriately defined. It, therefore, lays the framework for software design.
• While the team or product owner gets switched, either of them need not start from the beginning. This document will serve that purpose.

What does a good SRS look like?

The SRS document specifies how the intended software has to work in the intended environment. A good SRS should cover the following points:

Introduction

1. Objective
2. Document agreements
3. Desired audience
4. Added information
5. Contact information
6. References

Overall Description

1. Product outlook
2. Product purposes
3. User classes and features
4. Functioning environment
5. User environment
6. Design and implementation limitations
7. Conventions and dependencies

External Interface Requirements

1. Hardware interfaces
2. Software interfaces
3. User interfaces
4. Communication conventions and interfaces

System Features

1. Description and precedence
2. Outcomes/ Results
3. Functional requirements

Non-functional Requirements

1. Performance requirements
2. Security requirements
3. Vulnerability requirements
4. Software quality features
5. Project documents
6. User documents

Software System attributes

1. Reliability
2. Availability
3. Security
4. Maintainability
5. Portability

Other Requirements

Appendix A: Jargon/Glossary/Definitions list

Is SRS still relevant in Agile Era?

The ideologies behind the agile approach are to focus on providing value to the customer. This means that the effort we devote towards developing the product rather than spending time on unwanted things. This also refers to documentation, development team follows “Develop now Document Later”. But even documenting later is also so challenging because of all the changes that may come from user feedback. In sprints, the user stories are prioritized and are queued in the product backlog. Whereas in an SRS document, there is no attempt taken to prioritize the requirements.

So the Agile methodology is actually opposite to following an SRS based development methodology. If you are moving towards agile, remember that agile does not need an emphasis on skipping documentation, it just prompts the team to focus more on delivering value to the customer.

Last words

Although having an SRS at the start of the project now being considered an old school way in software development, but if you have a solid understanding of your desired product, a good quality, well-intended, and well-written SRS document can lead you towards a successful software product.

SRS can also act as a reference document for the Agile Teams so that they do not lose the vision of the overall product as envisaged by its original stakeholders.