1. A server computing device comprising: a processor; and one or more processor-executable instructions stored on a computer-readable storage medium of the server computing device, said processor-executable instructions including instructions that, when executed by the processor of the server computing device, implement: a runtime environment adapted to execute one or more model objects, said one or more model objects corresponding to a process device within a continuous process, wherein execution of the one or more model objects by the runtime environment comprises one or more system events and one or more aperiodic user events, a scheduler process of the runtime environment, said scheduler process implementing the one or more system events in accordance with a periodic schedule, an on-demand process of the runtime environment, said on-demand process implementing the one or more aperiodic user events in response to receiving a request for the user events from a user device, and an event manager process of the runtime environment, wherein the event manager process synchronizes implementation of the scheduler process implementing the one or more system events in accordance with the periodic schedule and implementation of the on-demand process implementing the one or more aperiodic user events, wherein the runtime environment executes the one or more model objects via only one of the scheduler process and the on-demand process in response to the synchronized implementation of the scheduler process implementing the one or more system events and the on-demand process implementing the one or more aperiodic user events.