The Wait activity suspends execution of the process instance and waits for a Notify activity with a matching key to be executed in another process instance. The key specified in the Notify Configuration resource specified on the Configuration tab and the Key field of the Input tab creates a relationship between the Wait activity and the corresponding Notify activity.
The same Notify Configuration shared configuration resource must be specified by corresponding Wait and Notify activities so that data can be passed from the process instance containing the Notify activity to this process instance. The schema in the Notify Configuration resource can be empty, if you do not wish to pass data between processes.
The Wait, Receive Notification, and Notify activities allow running process instances to communicate. See TIBCO ActiveMatrix BusinessWorks Process Design Guide for more information on inter-process communication.