A transition is the passing from one state to another. In the toolkit, a transition occurs when a specified event occurs and the process satisfies specified conditions. The name of the transition is the name of the event triggering the transition. A transition has an owning state and it identifies the actions the process is to execute and may identify the target state that the process will be in once it executes the action. If the transition does not identify a target state, it is an internal transition. The processor executes the transition's actions in the order in which they appear in the transition's external definition.

Unlike UML transitions, which require a one-to-one relationship between an action and a transition and have a guard condition for triggering the transition, a toolkit transition can have more than one defined action. For each of these actions, the process evaluates a set of guard conditions.

Because a processor can enter the same state many times during a flow, transitions to that state can specify whether the processor must perform the entry actions each time it enters the state or only the first time that it does so. The ignoreEntryActions parameter of the transition tag configures the processor so that it ignores the entry events on the second and all subsequent times it enters the state.