What makes a UML Composition different from an Aggregation or a regular Association?

The concepts of Association, Aggregation and Composition exist in UML since the first published versions, but the exact meaning of these concepts, especially the Aggregation still leads to heated debates among UML experts.

But before we go into the details, let’s have a look at how these concepts are defined in UML. I guess every UML user is familiar with the graphical notation, but how do these concepts look like in the UML (v 2.5) meta model?… Read more

There seem to be a lot of misconceptions about UML in the industry, but one of the most persistent is that UML is all about diagrams.

I’ve heard/read phrases like “UML is a collection of diagrams”, and even the Wikipedia page about UML mostly talks about the different diagrams rather then the actual elements and their structure.

Well let me tell you, UML is NOT about diagrams.

Even OMG thinks so as diagrams are hardly defined in the UML superstructure specification.… Read more