SAP Knowledge Base Article - Public

3160536 - How to re-use a 'decision logic' in DMN modelling

Symptom

Is it possible in any way to re-use a ‘Decision’ logic?

For example:
I have 5 different ‘Input Data’.
For each of these 5 inputs, the same decision needs to be applied.
So I can model it 5 times.
But when ever this decision changes. I have to change it 5 times as-well.

So I was wondering if there is a way to make a leading-subordinate kind of decision. So the 5 ‘subordinates' look to the one ‘lead’ decision. You change your ‘lead’ and the ‘subordinates’ all follow.

Resolution

Option 1: Outsource logic to a dedicated decision model.

Other decisions can be linked to this model if needed, instead of describing the same logic and inputs again. There is a separate section in our user manual, which describes how this works:

https://docs.signavio.com/userguide/editor/en/modeling_and_notations/dmn/decision_logic.html?#referencing-a-decision-of-another-dmn-diagram

Option 2: Using a business knowledge model (BKM)
This element is provided by DMN 1.1 and allows to apply the same logic on a different set of inputs. For example:

  • Logic: validate address (check zip code, street, etc.)
    This decision logic is needed for 2 separate decisions.

Decision A: Validate address for delivery
Decision B: Validate address for invoicing (if different)

Instead of describing the same logic multiple times, it could be described once in a BKM.
BUT: We currently do not support the usage of BKM yet, because we've found no practical example so far, on which the same logic is used on a different set of inputs.

The applying logic depends rather on the set of inputs and required most in time a separate decision.


Keywords

KBA , BPI-SIG-PG-EDT , Process Governance Editor , How To

Product

SAP Signavio Process Governance all versions ; Workflow Accelerator by Signavio all versions