BPDM (Business Process Definition MetaModel) project has started few
years ago. The goal of this project is:
"This specification has been through a multi-year process within the
Object Management Group (OMG) to define a common meta model for the
various process notations, methodologies and standards. BPDM also
serves as the meta model behind the popular Business Process Modeling
(BPMN) notation."
The last proposal for specification has been submited at the end of last
month. You can visit the site http://www.modeldriven.org/web/bpdm and
see the specification.
I see a lot of advantages:
1) A lot of people have worked on this model and i think they fixed a
lot of potential problems
2) This is linked with the BPMN project, the standard in terms of GUI
approach
3) This is the OMG standard meta model
4) It covered XPDL and BPEL