How to write an SRS (Software Requirements Specification Document)

How to write an SRS (Software Requirements Specification Document)

The software development process usually starts with writing a Software Requirements Specification Document also known as SRS. This is the core paper that will guide all the participants of the process — software developers, designers, QA-engineers, project managers, and others — to the final result. Let us now see what should it cover and why is it necessary.

What is SRS?

SRS is a document describing all the details of the future product as well as the tools and approaches that are going to be used in the development process. It keeps a huge amount of relevant information including the following:

  • Functional requirements;
  • Non-functional requirements;
  • Product functionality;
  • The technology stack that is planned to be used;
  • The whole development process;
  • Scheduling and delivery estimates;
  • Risks and how to minimize them;
  • Use cases and user characteristics;
  • Constrains, assumptions, dependencies.

Why is it necessary?

SRS can be compared to a map: it is a plan showing the route to the final destination. The more accurate and detailed it is, the fewer chances your team has to get lost. That is why it should cover all the turns, stops, places to avoid, transportation to use, and so on.
SRS helps everyone involved in the project to be on the same page as well as allows checking if everything goes as planned and all the requirements are fulfilled.

SRS - How to? Step by step

5 Steps to a good SRS

Having 19 years of experience working on customer projects, we have come up with 5 steps that might help to create a good SRS. Here they are:

Step 1: Outline

The first thing to do should be an outline of the future software requirements specification document. If your company does not have its own template and you do not have enough experience in writing SRSs, we recommend searching for the existing examples on the Internet. Study them to get the idea of how it all looks like, choose the one most suiting your project and adapt it to your needs.

Step 2: Details

The next step will be filling in the outline. This is the longest and hardest part of work and should be done by someone who has an excellent understanding and vision of the future product in order to describe everything thoroughly. At the same time, SRS should be good-written so that everyone involved could understand it as well as to avoid any double interpretations that might result in miscommunication between the team members. If you can, engage a business analyst and technical writer for this part of the work.

Step 3: Visualization

Images and graphics are always a good idea. Especially inside a huge document consisting of plain text (as most of the SRSs are). Charts, infographics, and other images help the readers to get the idea faster and easier. So, if there is an opportunity to visualize some data, use it.
Speaking of data, we recommend eliminating inessential and unuseful information: the document will be big anyway, it is better not to steal attention from the things that really matter.

Step 4: Approval

When the SRS is complete, all the stakeholders should read it carefully and leave comments or additions if they have any. After you make all the edits, they should read the document again and approve that everything is correct from their perspective.

Step 5: Availability and updates

Software development implies being up-to-date and implementing new features as soon as they are required. That is why the SRS you’ve created is likely to be changed in the future. It is important to update the information in the document and to keep it online so that everyone can easily reach the current version.

The Bottom Line

Being a custom software development company, SCAND offers the services covering all the stages of the development: from consulting and creating SRS to the maintenance of the ready product. In case of any questions or the need for software development, do not hesitate to contact us.