SAP Knowledge Base Article - Public

3590681 - Output of DMN Task in Process Governance is empty

Symptom

  • The DMN task used in Process Governance is not outputting the information from the DMN decision.
  • DMN simulator shows the correct output, but the information is not accessible from the Output when used as a DMN task in Process Governance

Reproducing the Issue

  1. Create a DMN diagram in SAP Signavio Process Manager using the Unique Hit Policy, have it be able to "hit" 2 rules at once and publish, e.g. >10 and >20
  2. Create a Process Governance process, use a form as the trigger, where a number can be input, add a DMN task and a User task.
  3. In the DMN task, select the DMN created in step 1. Use the number from the trigger form as the input, and create a new Text field for the output.
  4. In the User task, select the Form tab, select "Reuse a field" and select the Text field from the output of the DMN task, select Read Only and publish the process.
  5. Start a new case for the process just created. Input the number 21 and check the User task which shows the output, notice that the form is empty.
  6. Start a new case as above. Input the number 19 and check the User task which shows the output, notice that the form shows the output for the rule which is >10.

Resolution

As the DMN decision is able to "hit" 2 rules, it needs to be changed so that only 1 rule can be "hit". Changing the Hit Policy from Unique to First will ensure that there is only 1 rule "hit".

Make sure that the decision table is tailored to your requirements, but only 1 rule can be "hit" for the output to be usable in Process Governance.

See further DMN task limitations here:
SAP Signavio Process Manager - DMN Task

Keywords

DMN task, SAP Signavio Process Manager, workflow, business rules, Hit policy, variables, Process Governance, DMN, DMN diagram, DMN model , KBA , BPI-SIG-PM-MOD-SIM , Simulation for SAP Signavio Process Manager , BPI-SIG-PG , SAP Signavio Process Governance , BPI-SIG-PM-EXP , Explorer for SAP Signavio Process Manager , How To

Product

SAP Signavio Process Governance all versions ; SAP Signavio Process Manager all versions