Event-B is an emerging formal method with good tool support for various kinds of system modelling. However, the control flow in Event-B consists only of non-deterministic choice of enabled events. In many applications, notably in sequential program construction, more elaborate control flow mechanisms would be convenient. This paper explores a method, based on a scheduling language, for describing the flow of control. The aim is to be able to express schedules of events; to reason about their correctness; to create and verify patterns for introducing correct control flow. The conclusion is that using patterns, it is feasible to derive efficient sequential programs from event-based specifications in many cases.