SYSML14 — SysML Issue Lower bounds on multiplicity not consistent with diagram

In SysML 1.3

11.3.1.1 Activity constraints

“The lower multiplicity at the part end must be zero.”

The diagram above Figure 11.1 on the previous page does not indicate 0 as the lower end. The default for a composition relationship at the part end is 1..1 and does not include 0.

However, as you fix the diagram consider eliminating the constraint 3.

I believe this constraint has been eliminated from UML 2.5 (in the works). The proper constraint is something like. (Conrad will know what’s in the UML spec). If the part end action starts running when the parent activity is started, and continues until the parent activity is ended, then the minimum multiplicity is non-zero. Otherwise, the lower multiplicity at the part end must be zero.

Whether the constraint is fixed or not, the diagram must include a lower end of zero.

Recommended fix, eliminate the constraint and fix the diagram

11.3.1.4.1 Constraint 3

Similar to above. The BDD in Figure 11.5 would need to explicitly be marked to allow for 0.

This constraint was not changed in UML. Recommend the diagram be fixed

Remove Constraint [3] in 11.3.1.1.1 (Notation) for the reasons filed. Figures 11.1 and
11.5 show generic notation. They aren’t examples, so do not need to have
multiplicities.