Extending Conceptual Schemas with Business Process Information

Table 2

Constraints for merge gateways.

Merge gateway	Process constraints
	- All A activity instances have as a previous activity instance a completed activity instance of type B1 or…or Bn; context A inv: previous->size()=1 and previous->exists(b ∣ (b.oclIsTypeOf(B1) or …or b.oclIsTypeOf(Bn)) and b.status=‘completed’)
	- Each 𝐵1⋯𝐵𝑛 activity instance is followed by an A activity; context Case inv: status=‘completed’ implies activity->select(b ∣ b.oclIsTypeOf(B1) or …or b.oclIsTypeOf(Bn))-> forAll(b ∣ b.next->exists(a ∣a.oclIsTypeOf(A)))
	- An A activity instance must wait for at least an incoming flow; context A inv: previous->select(b | (b.oclIsTypeOf(B1) or …or b.oclIsTypeOf(Bn)) and b.status=‘completed’)- >size()≥1
	- An activity instance of type A must wait for a set of activities 𝐵1⋯𝐵𝑛 to be completed; context A inv: previous->exists(b ∣ b.oclIsTypeOf(B1) and b.status=‘completed’) and…and previous->exists(b ∣ b.oclIsTypeOf(Bn) and b.status=‘completed’)
	- Each set of completed 𝐵1⋯𝐵𝑛 activity instances must be related with an A activity instance; context Case inv: status=‘completed’ implies not (activity->exists(b ∣ b.oclIsTypeOf(B1) and b.status=‘completed’ and not b.next->exists(a ∣ a.oclIsTypeOf(A)) and …and activity ->exists(b ∣ b.oclIsTypeOf(Bn) and b.status=‘completed’ and not b.next->exists(a ∣ a.oclIsTypeOf(A)))