The pub.prt.CallActivityModel and pub.prt.SubprocessModel document type enables you to generate multiple instances of each callable or referenced process you invoke. For example, suppose you are creating a purchase order handling process, and you already have added a call activity step (configured with dynamic process behavior) that invokes an existing process model that calculates the shipping time for an inventory item.

If the purchase order process is handling a purchase order with 10 line items, you can configure the call activity step to invoke the shipping time calculator process 10 times—once for each line item—by implementing standard looping in the call activity step.

By mapping the key data from each line item into a separate document, this document can be passed to the dynamically invoked process for calculation. Each instance of the shipping time calculator process returns an output document to the purchase order process with the results of the calculation for each line item.

These return documents are maintained in the process pipeline as a named output document lists for callable processes, and as a document list for referenced processes. For more information, see pub.prt.CallActivityModel and pub.prt.SubprocessModel.