1. A computer system having a physical computer-readable medium including computer-executable instructions comprising at least a portion of a supervisory process control and manufacturing information system application distributed to one or more networked computer devices and having a layered architecture on the one or more networked computer devices, the portion of the supervisory process control and manufacturing information system application comprising on a single computer: application objects modeling entities within a process control system; one or more engine objects hosting execution of the application objects in a run-time environment; and a platform object, corresponding to a physical computer system component for executing the one or more engine objects and the application objects, and wherein the platform object hosts, in the run-time environment, the one or more engine objects.