Business Process Definition Metamodel (BPDM) 
- [wiki](https://en.wikipedia.org/wiki/Business_Process_Definition_Metamodel)
- [omg.org spec](https://www.omg.org/spec/BPDM)
- [BPMN 2.0 killed BPDM](https://modeling-languages.com/has-success-bpmn-20-killed-bpdm-business-process-definition-metamodel/)