The Most Important Diagrams

The other day, a customer asked what I thought were the most important diagrams when creating a UML model. Organizations new to modeling often ask the same question, so I'm going to spend the next few days answering it.

Always remember that the purpose of modeling is to help one understand the system. Both the UML and SysML are full of diagrams and subtleties that make the languages richer and more expressive, but only if the readers understand the full content. In my practice, I see developers with all levels of experience and comprehension of the UML. As one would expect, the vast majority are somewhere in the middle. They know the diagrams they use frequently very well and are less well versed in those they seldom use.

Use the diagrams most people understand: Use Case Diagrams, Activity Diagrams, Sequence Diagrams, and State Charts.

In the next few posts, I will describe each of these diagrams and how I use them.