RAAML11 — Unclear whether a part of a composite can be reused in another composite

An instance of a part can be part of exactly one composite instance, but there could be many options for the composite. For example the same ScenarioStep could be part of many Scenarios. Of course, each instance of the ScenarioStep will occur only in one Scenario instance.

In order to allow this, the multiplicity on the whole side of the composite relationship in figure 9.22 must be 0..1.

In this figure this multiplicity is not shown. This leads to two possible interpretations. According to UML the default is 1, but according to SysML the default is 0..1. Now, the General Concepts Library is a SysML model, hence we could assume that it is 0..1.

However, this default is just a notational thing: "SysML: These multiplicities may be assumed if not shown on a diagram.". In order to make it into the xmi-file the multiplicities must be set explicitely. And in the current xmi-file the multiplicity is not defined. When it is opened by Cameo, it sets the value explicitely to 1. You might consider this a bug in Cameo, but I guess this behavior is within the specification.

So my question is: What was the intention? Should a scenario step only be part of one scenario? Then the multiplicity must be 1 and this should be made clear in the diagrams. Or can it be part of many scenarios? Then the multiplicity must be 0..1 and this should also be shown in the diagrams. And it should be defined in the xmi-file.

The same question needs to be answered for all composite associations in the libraries, e.g. Risk to Effect, Event and HarmPotential. ScenarioStep is just one example for the issue.

Composite relationships should have 0..1 multiplicity at the composite end

Most of composite relationships should have 0..1 multiplicity at the composite ends. This is a larger effort for the working group with almost no impact to end users. Thus the working group will focus on it in the next release.