I assume you are attempting to display the Serial Number of an active task on this task form?  I believe a valid Serial Number will usually only exist while the Task/Client event is active:

When integrating with SmartForms, it will create a State and add a rule to open this task on the form; in this context, the applicable Serial Number will be available:

In the open worklist item rule:

In this Rule, the Serial Number can be mapped to a data label control in the out put mapping for the application Activity:

Thank you.

I was hoping to use the start a workflow rule to output the serial number to a data label  OR  to pass the serial number into a data field in the workflow, then to output that data field into a data label.

Now sure how I will use open worklist item, in the form I have, but if there is no alternative, I will have to rethink my form.

Hi SanaShah,

  Start Workflow Action rule is only responsible to start workflow, once process instance is created  rule execution will completed and return process instance id in output mappings.

• SN is combination of “Process Instance ID”(for e.g. 9865) and “Activity Instance Destination ID”( for e.g. 21)
• Which is appears as    Process Instance ID_ Activity Instance Destination ID (9865_21).
• As we already have Process Instance ID, we are only required to get “Activity Instance Destination ID” to generate SN.

To get “Activity Instance Destination ID” follow below steps

• Add rule “Execute a SmartObject method “and select SmartObject as “Activity Instance Destination” which is available under Workflow reports.

• Now concatenate both Data Label’s having “_” in between, which return SN.

Let me know if this helps you.