Stephen and Sally never supplied a pre-packaged “Shlaer-Mellor Runtime Engine” in the form of operating system or middleware services. Instead, they defined rules for the execution of domains modeled using the Shlaer-Mellor Method. Examples included the Time and Event Rules, such as, “Event ordering shall be maintained between sender/receiver pairs.” (Which tacitly implies that ordering need not be deterministic among non- sender/receiver pairs.) Another rule is referred to as Accelerated Event to Self which states that, “Events sent from an instance to itself shall be processed ahead of events sent from other instances.”
A Shlaer-Mellor runtime architecture can be modeled (with Shlaer-Mellor xtUML) just as any other subject matter. Here are a class diagram and dispatcher class state machine of an architecture which realizes a runtime that obeys the time and event rules.