Many business process models contain parallel processing paths, where process data is handled in different paths (also know as tracks) within the process. Eventually, these parallel paths come together in a gateway or join step. In such cases, one or more of the incoming transitions may not complete because of the failure of an upstream step or some other processing condition.

An incomplete transition of this type is also referred to as a dead path, meaning that the required join information will never be provided. As a result, the join step could enter a permanent waiting state, waiting for information that will never arrive.

To avoid this condition, the Process Engine issues an internal dead path notification to the downstream join step, behavior introduced in version 8.0. This notification informs the join step that the transition is incomplete and will never be fulfilled, thus preventing the join step from waiting indefinitely.

For more information, see How Incomplete Transitions Affect Join Steps and Gateways.