Which process model notation is maintained by the Object Management Group?

The correct choice is Unified Modeling Language (UML), which is maintained by the Object Management Group (OMG). UML is a standardized modeling language used to specify, visualize, develop, and document the artifacts of software systems. It provides a set of graphic notation techniques to create visual models of object-oriented software-intensive systems, allowing for effective communication and understanding among developers and stakeholders.

UML incorporates diverse diagram types, which can represent various aspects of the system, including structure, behavior, and interactions. As part of OMG's responsibility for maintaining and evolving UML, this ensures that it adapts to the needs of the software engineering community while remaining consistent and usable universally.

Other process model notations mentioned, such as Business Process Model and Notation (BPMN), Event-driven Process Chain (EPC), and Value Stream Mapping (VSM), do not fall under the management of the Object Management Group. BPMN is specifically focused on business process modeling, EPC is used primarily in business process management, and VSM is a lean management tool aimed towards identifying and reducing waste in processes. While these tools are valuable in their own rights, they are independent of OMG's oversight, making UML the unique choice maintained by this organization.