Delete a Signal from being used by any subscribing Process or Collection in your organization.
Delete a Signal
When a Signal is deleted, it can no longer be referenced from other Process model elements throughout your ProcessMaker Platform instance. If a Process model element is already subscribing to a Signal, that Signal can not be deleted.
Permissions
Your user account or group membership must have the following permissions to delete a Signal unless your user account has the Make this user a Super Admin setting selected:
Signals: Delete Signals
Signals: View Signals
See the Signals permissions or ask your Administrator for assistance.
Deleting a Signal from the Signals page cannot be undone.
Follow these steps to delete a Signal:
View your Signals. The Signals page displays.
Click the Delete icon
for the Signal to delete. The Caution screen displays to confirm the deletion of the Signal. 
Click Confirm. The following message displays: The Signal was deleted.