VDML11 — Problematic constraint on Role, Participant and Collaboration

Sub-clause 7.2.1.2.3 (Assignment Class), page 36, has a constraint that says, page 37: “A Role MUST NOT be assigned to more than one Participant that is a Collaboration, unless the additional Assignments are context-based, i.e., contained by DelegationContext”. This constraint has several problems. It ignores the fact that participations can be indirect, through a chain of assignments (“roles of roles”). It also ignores the fact that context-based assignments are not only possible with delegation contexts (i.e., children in the context tree), but also with scenarios (the top of context tree). Furthermore, this constraint was written with Position roles in mind, but leaves too much room for invalid situations for other types of roles.

Replace constraint

Replace the problematic constraint by three other constraints.