BKPMN — BKPMNModel attributes - various.

Class BKPMNModel attributes:

purpose: has its own type Purpose. Couldn't the purpose be included in inherited documentation? I would have expected that there could have been an attribute SCEElement.purpose: Documentation might have been just as good, and one less class.
manifest: is the manifest not generatable from the structure? Maintaining a separate documentary manifest is likely to duplicate and become inconsistent w.r.t. the Model structure.