There is no legally prescribed structure for a functional specification: Companies are free to compose them as they choose. However, there are certain content elements that have become standard practice. It’s important that all teams involved are named, for example. Essential requirements for project implementation also belong in the functional specification.
What’s more, the entire process of the project should be described, with everything it entails. The following structure is recommended. You can use it as your functional specification template. Or you can adjust it according to your needs.
1. Introduction
Besides explicitly naming the client and contractor, this section should also briefly describe the project. Address what the project involves and what the final outcome should look like. It’s important that someone who hears about the project for the first time can understand what it’s about.
2. Order
This is where the order is formulated. Build on the description in the introduction and go into greater depth with explanations. Describe the objectives of each phase, as well as the general conditions and any special considerations with respect to the project.
3. Existing systems or products
Are there any project-related systems or projects that have already been completed by the client and no longer need to be implemented by the contractor? If they are also relevant to the project, you should also mention them in the functional specification.
4. Teams and interfaces
Name precisely who is involved in the project and where the interfaces are. You should also list the communication channels in this section.
5. General conditions
You should state the entire processing period here, for example. You can also describe the planned operating times and working hours.
6. Technical requirements
Here you should specify what you need to implement the project – such as hardware and software. It is also advisable to list which equipment you will require for each task.
7. Problem analysis
Summarize the most significant problems you expect to encounter. It is especially important to define a solution in advance to the most likely problems, as this will save time later. Also consider possible but unlikely problems.
8. Quality
What requirements do you have in terms of quality? You should also explain how you will implement quality assurance, control, and acceptance.
9. Project development
Describe exactly when each phase will occur and how the overall project is organized.
This list is just an example of what a functional specification could look like. There are many different projects that may require more or fewer points. But it’s important that the specification sheet and functional specification match and complement each other.