UML25 — 17.1.5 Interaction Diagram Variants p 607

What is the rationale for making Timing Diagrams optional for tool compliance?

Description:
This clause states, “Conformant UML 2.5 tools are not required to implement Timing Diagrams.” UML 2.5 takes the bold step—which I favor—of eliminating the formal compliance levels, and then carves out caveats in the fine print. What is the rationale for making Timing Diagrams part of the UML spec., but then stating that they’re optional for tool compliance?

Most existing implementations do not implement timing diagrams, so this recognizes established practice.
Disposition: Closed - No Change