As mentioned here and here, one of our EA projects is "Common methods and templates for requirement specification".

In our organization we have chosen Use Cases for identifying, structuring and documenting functional requirements. I am convinced of the strength of Use Cases and have used it a lot at my former working place. The biggest strength is the focus on the user, because Use cases encapsulate functional requirements in the Users cases and working situations. After the requirement process, you can use the Use cases in the design-phase, test-phase and making of user manuals and online help, while u have 100% focus on the users and requirements in the rest of the project!

I have evangilize Use cases to our business departments (I am supporter of Event-driven Use cases) and after explaining the concept for the business people, they can easily understand it. In next month we will use Use Cases to specify three systems, which are based on VANG and Focus and must be modernizied to MS .NET.

It is important to realize that working with Use cases is an iterative process, where the Use cases are becoming more general and can there for be reused by more actors. More over is more and more business concepts identified until you almost have a complete business concept model, that in the design phase can me transformed to a datamodel.