A workflow can launch another workflow as an activity.

The parent workflow triggers the subflow and then waits for the subflow to complete before continuing. Run the workflow validation tool prior to publishing to detect missing subflows and other dependency problems, such as those involving update sets.

The Workflows tab in the Workflow Editor contains a list of the workflows available for use as subflows.

Figure 1. Workflows available to use as subflows
Workflows available to use as subflows

Make sure that the selected subflow is active. If the subflow is inactive, the main workflow will hang with a Loading message. If you place an inactive subflow into a workflow, the subflow appears with a red banner, indicating that it cannot run. An active subflow is highlighted in blue when selected.

Figure 2. Workflow with active subflows
Workflow with active subflows

Subflows and the Create Task activity

If a workflow contains a Create Task activity that has executed on the current record, additional task activities in the workflow might not execute as expected.

This can happen when the same subflow containing a Create Task activity runs more than once in a parent flow. When the subflow reruns and attempts to execute the Create Task activity again, the system reopens the first task activity instead and does not create an additional task.
Note: An alternative to creating duplicate subflows that use the Create Task activity is to add a Run Script activity to the workflow that creates a task with a script.
Figure 3. The same create task activity runs twice in a workflow
In this configuration, the workflow does not run the same subflow containing a Create Task activity more than once. This allows the workflow to create additional tasks.
Figure 4. Running different subflows containing the Create Task activity