BACM11 — Sequencing of ValueStreamStages

ValueStreamStages are commonly ordered in display.
There is a question about whether this implies an operational ordering that disallows temporal overlap and what semantics this ordering might be based on. This issue also relates to BACM11-3 concerning entry and exit criteria for ValueStreamStages.
There is also a technical issue. UML allows for ordered associations. In practice these involve tagging links with an ordering value that is used to control the order in which links are iterated. This is also permitted in MOF. However, the actual ordering cannot be specified for the meta-model elements, only for their instances (which are the model classes).
One solution would be to add a property to the ValueStreamStage whose value controls the ordering. However, MOF properties are typically translated to OWL as DatatypeProperties and have semantic consequences for individuals. A better solution for OWL would be to define an AnnotationProperty that either orders ValueStreamStages directly or defines an ordering value. This implies a UML/MOF Comment attached to each ValueStreamStage, whose body contains a predefined keyword and an ordering value. Alternatively, a Comment could link to two ValueStreamStage instances and specify the ordering relation between them.