YaSM and USMBOK (Universal Service Management Body of Knowledge)
USMBOK (Universal Service Management Body of Knowledge, owned by Virtual Knowledge Solutions International Incorporated) is a service management framework that continues to gain in popularity.
As the authors of USMBOK state, "USMBOK includes a set of generally accepted terms, methods, concepts and best practices". USMBOK specifically refers to a "service management system", a term which figures prominently in ISO 20000).
For those reasons, it was both desirable and feasible to take the guidance in USMBOK into account when developing YaSM. YaSM, however, cannot claim to be a "USMBOK process model".
The USMBOK guide includes a description of the service life cycle, representing significant service stages from identification of an opportunity to provide a service to service retirement.
In the YaSM Wiki you'll find a special page that describes how the ideas behind USMBOK are represented in YaSM, in the form of a table with an overview of how each stage in the USMBOK service life cycle relates to one or several YaSM processes.