Why Use the UML?

The UML is used primarily for communication—with myself, my team members, and with my customers. Poor requirements (either incomplete or inaccurate) are ubiquitous in the field of software development. The UML gives us tools to gather better requirements.

The UML gives a way to determine if my understanding of the system is the same as others'. Because systems are complex and have different types of information that must be conveyed, it offers different diagrams specializing in the different types of information.

One easy way to see the value of the UML is to recall your last several design reviews. If you have ever been in a review where someone starts talking about their code and describes it without a modeling language like the UML, almost certainly their talk was both confusing as well as being much longer than necessary. The UML is not only a better way of describing object-oriented designs, it also forces the designer to think through his or her approach (since it must be written down).