Transitions
Transitions describe the flow of processing. A transition is represented by an arrow between two activities or groups of activities in a process definition. The arrows are unidirectional, and you cannot draw a transition to a previously executed activity. Control flow in a process definition must proceed sequentially beginning with the starting activity and ending with the End activity. If you wish to perform looping, use groups to specify multiple executions of grouped activities (for more information on groups, see Grouping Activities).
After an activity or group completes processing, all transitions whose conditions are met are taken. You can have transitions from one activity to many other activities. Therefore, you can have several branches of activity processing in your diagram.
Each activity in a process definition must have a transition to it, or the activity is not executed when the process executes.
The following figure illustrates examples of valid transitions in a process.
Valid transitions
The following figure illustrates an invalid transition.
An invalid transition
A transition is taken depending upon the condition specified on the transition. When a transition is created, you may specify whether the transition is taken always, only when an error is encountered, only if no other transitions are taken, or when a custom-specified condition based on process data values is true. For more information, see Conditions.