Modeling as a Discipline

Most people, systems engineers included, typically find it easier to write a long description of a topic rather than a succinct, concise summary - this is analogous to the challenge of modeling.

The question isn't so much what to include, but rather what to leave out.

One of the advantages of model based system engineering is precisely this - it encourages engineers to create models that are descriptive, crisp and concise. The long (and sometimes rambling) sentences of document based processes are replaced with clear and laconic diagrams that unambiguously describe the requirements, the structure and the behavior of the system.

There are those who describe modeling as a hermetic discipline and speak of it as one of the 'dark arts' practiced by alchemist engineers robed in purple gowns. This underlies the issue that modeling is seldom taught as a subject in our universities, nor are there vast quantities of literature on the topic, making it appear to be a mysterious art rather than what it is - a science that can be learnt.

There are a number of different types of model including:

• Scale Models
• Physical Models
• Abstract Models

In this guidebook we are most interested in Abstract models, as they are the models we will typically be creating using Enterprise Architect and the Systems Modeling Language.

These models are - as the name suggests - abstractions of reality that seek to highlight the most important aspects of an entity, subsystem or system, while leaving out the things that are not important or are irrelevant from that viewpoint. For more information see the Models Help topic.