A Unified Procedure Step (UPS) represents an arbitrary unit of service. Unified Procedure Steps are generally scheduled in response to a Requested Procedure, although a UPS may be triggered by other events, such as a scheduled calibration, completion of prior work in a pipeline, etc.

The Unified Procedure Step (UPS) unifies the details of the procedure step that has been requested, the progress details during performance, and the details of the procedure step actually performed. The details can describe the specific service activity, the subject and/or data acted on, the originator and context of the request, the human/equipment/application resources involved, the priority, date, time and location of the activity, and references to resulting output data.

Normally the details about the activity as performed correspond to the details of the activity as requested, however real-world conditions may dictate that what is actually performed does not correspond exactly with what was requested or scheduled.