Process improvement professionals such as Black Belts are focused, primarily and not surprisingly, on the world of designing, improving, and otherwise changing (one hopes for the better) processes. But when one asks Black Belts about whether they work to a standard model of process hierarchy and definitions one gets a hodge podge of different answers (or no answer).
One framework that I suggest that organizations consider as their standard process architecture is SCOR or the Supply Chain Operations Reference. It is maintained by the Supply Chain Council (http://supply-chain.org/).
They have standard process definitions for 3 levels starting at the enterprise level, proceeding to the operations level, and then at level 3 describing activities. Levels 4 and 5 are focused on workflow and the transactional level; these are company and/or industry specific. As a starting point for process management-related structures, I think organizations need to explicitly examine the strengths of the SCOR approach.
There are many other process structure definitions out there, all with good points as well. One advantage of the SCOR model is that it has a large installed base of users in industry which could make it easier for one organization to work with others in their supply chain if they all worked from SCOR. In addition, the principles and benefits of Lean Six Sigma need application at the supply chain level to get at the big opportunities and big sources of waste.