Some CMMN concepts contrast sharply with "traditional" process language concepts as can be found in BPMN. For instance there is no strong "happens before" relation between activities as induced by sequence flows in BPMN. In CMMN, activities have a more "causal" relationship.
As a result, it is not very convenient to map CMMN to the existing PVM AtomicOperation implementations which are written with Graph Execution semantics in mind.

Nevertheless it is attractive to reuse the same base structures and programming model absrtactions for CMMN as for BPMN.

=> Provide a minimal core infrastructure in process engine which provides base classes for

• STATE: executions & variables,
• STRUCTURE: graph model,
• BEHAVIOR: AtomicOperations & ActivityBehaviors