Introduction to modelling

#ArchitectureModelling #ArchiMate

Experienced modellers emphasise that they do not simply draw pictures, but rather model. But what is modelling? When modelling, images are created, but it is not merely drawing. The elements in the images carry specific meanings (e.g., process, application), as do the connections between the elements (e.g., data transfer, service provision). Most often, these images are created using a modelling tool, where the elements and their connections form a web and structure. The web of elements and their connections is built through the drawing of images. From time to time, the modeller checks that the network is intact, meaning there are no contradictions or duplicates. This entire process is called modelling. Before both the images and the element network are complete, several iterations are usually required.

To model, a language is needed. A language (e.g., ArchiMate®) specifies what the different elements look like. For example, a business process is represented by a rectangle with an arrow in the upper right corner. The business process is yellow. A data flow, on the other hand, is a specific kind of dashed-line arrow.

ArchiMate® language is also a standard. In that case, multiple parties have participated in its development, and the standard is published as a documented guideline. If the standard is open, anyone can use it. Developing notation is surprisingly labour-intensive. For the notation to work in various contexts, to be unambiguous and consistent, many rounds of editing are required. In practice, this means a lot of work. The challenge of creating standards has become a widely recognised fact, which is why custom-made notations are seen less and less often.

There are many benefits to using a standard notation. Time is not wasted on developing a custom language, and it makes it easier to read and interpret the diagrams. There's no need to guess what each symbol means as long as the notation remains the same. Currently, ArchiMate® has achieved the status of a de facto standard. Previously, each modelling tool had its own notation. A standard notation greatly simplifies the life of a modeller. When changing tools, workplaces, or consultancy assignments, the notation stays the same. It becomes easier to transition from one task to another.

Of course, the notation must be learned, and this takes time. There is material available online, but often some kind of course is also necessary. Notations are quite comprehensive and expand with each version. The benefit of attending training is that the instructor typically knows which areas are more essential than others.

Modelling has thus become more formal, standardised, and, overall, more professional. Despite all this, modelling remains creative expert work. It requires the ability to distinguish between what is relevant and what is not, to ask the right questions, and to create images that are communicative and understandable. Even someone unfamiliar with the notation can read architectural diagrams correctly, as long as the terminology is clear. It is fairly easy to deduce that "the blue" boxes are applications when their labels bear the names of familiar systems.