$PMWorkflowRunInstanceName returns the workflow run instance name as a string value. Use $PMWorkflowRunInstanceName with any function that accepts string datatypes.
Use $PMWorkflowRunInstanceName in a mapping, a mapplet, workflow links, or in workflow tasks such as Assignment and Decision tasks. You can also use $PMWorkflowRunInstanceName in input fields that accept mapping or workflow variables. For example, for a concurrent workflow with unique instance names, you can create unique target files for each run instance by setting the target output file name in the session properties to “OutFile_$PMWorkflowRunInstanceName.txt.”
Or, you want to use a post-session shell command to create an indicator file used by a predefined Event-Wait task. In the shell command that generates the indicator file, use $PMWorkflowRunInstanceName in the indicator file name to ensure that one workflow run instance does not delete an indicator file needed by another workflow run instance.