Define process maturity - Best practice

Dear Aris community,

I am looking for the best practice to define the process maturity of processes.

We want to classify our processes in 5 categories, similar to the ones in this post. (Every single process - not the organization)

http://www.ariscommunity.com/users/frlu/2009-03-09-enterprise-bpm-framew...

Is there an attribute or maybe another way to accomplish that?

Thanks

Fabian