Determining what diagrams to produce

Before we get into the various types of diagrams that you can produce, we need to introduce a couple of concepts, the concepts of the view and the viewpoint. If you're involved in a project where a single diagram is supposed to explain everything you need to know about a system or application, then drop the diagram, turn around, and run. Such a diagram cannot exist.

Some diagrams claim to do so, but they are usually far too big, far too busy, and don't convey a quarter of what is needed. They usually follow no standard and are created by those with little or no modeling experience. They make little sense except to their creator. The biggest problem with such diagrams is that they tend to convey a single set of concerns, those of the creator.

But please be careful, and be kind! These folks may have expended a lot of time and effort. They are often very knowledgeable and very proud of their work. The last thing you want to do is to...