DMN12 — alternative indication of reusable logic in DRD

In the metamodel/XSD, decision logic is contained in a decision element, hence not reusable. To reference reusable decision logic, decision invokes BKM, which is reusable. The semantics are clear, but representation of the decision and BKM as separate graphical elements in DRD is visually inefficient. It creates unnecessary clutter in the DRD (Fig 63 is a prime example). BPMN solved this problem in a better way, and I suggest DMN should allow the same. In BPMN a subprocess definition is embedded in the parent process so to reference reusable subprocess, it uses a call activity. The call activity shape is same as subprocess except it has a thick border style. The diagram does not contain both subprocess and call activity, just one or the other. I would like to propose that a decision shape in DRD with a thick border be used to mean the decision invokes a BKM (with name generated from the decision name). No metamodel or schema changes required; this is merely alternative graphical notation. In a DMN tool, typically clicking on the decision will hyperlink to the decision logic (DT or literal expression), whether that logic is embedded in the decision or reusable. This distinction is mostly important to programmers, not modelers, so should not unnecessarily complicate the diagram.

subsumed by invocable decision service

no longer an issue after invocable decision service feature added.