The conventional power system domain includes various utility business processes that are carried out by multiple market participants. In the conventional setup, these processes are typically captured through various local representations understandable by the concerned actors in their respective subdomains. The heterogeneity in process representations can result in problems of traceability, transparency, time-trackability, and interoperability across actors and software systems. To orchestrate the utility business processes, the IEC has recently started an activity entitled “IEC 62325-451-2:2014” for representing the “energy scheduling business process” of the European market in a standardized way. Along similar lines, this paper presents a process ontology along with a systematic methodology for building process models of end-to-end process operations of power utility. The process ontology consists of power system process modeling artifacts such as process, participant, activity, gateway, event, and event-based subprocess. For representing events and chronology of task execution, the common information model (CIM) can be adopted, which is expected to act complementary to process ontology semantics. An energy scheduling application is considered as a case study, wherein the proposed process ontology artifacts and the CIM ontology are used for building process models for an “energy scheduling business process” in the Indian power grid context.