A lot of (Functional) Designers of Software Systems think they design on behalf of the development department. The question remains: is this true? ‘Cause then we might ask ourselves what they need inside the document to make the most of it. Why is the main question on the Design part. This is because the setup for a Functional Design can be interpreted very different. Where the one organization tells us it’s for the Business to understand what the software will be able to do and how, the other organization states that the design is there to support the IT department in making a technical implementation of the wishes.
Both interpretations are wrong, in my eyes. This is because the Functional Design should embrace the possibility to function for both parties, Business as well as IT. It can be a helpful product when it comes to Aligning the IT department towards the Business (or the other way around). And this is exactly why UML isn’t sufficient.
The Universal Modelling Language is designed to define something understandable. And it certainly helps. It just isn’t for the Business. There are few people outside any IT department that understand UML sketches or models. This is, because we invented it and it’s only used to model software with. Therefore, UML does not belong within the Functional Design.
UML does belong, however, within the designs an IT department needs. It can be very flexible and understandable. For designs that come from out the business, you probably need another modelling language, or just plain words and some pictures, never mind the model.
