How do the "includes" and "excludes" operators work in Workflow rule criteria?

Question

Does anybody know how the "includes" and "excludes" operators work when setting up rule criteria for workflow rules?

The only documentation I've found on this is located at https://help.salesforce.com/articleView?id=filter_operators.htm&type=0&language=en_US&release=204.14 - this is good documentation, but since it is filed under Reports & Dashboards I get a little uneasy that it might be inaccurate.

My understanding is that the "includes" and "excludes" operators are only available when the field you've chosen is a multi-select picklist field (as the documentation states). These operators seem to work similarly to the "equals" and "not equal to" operators, except that multi-select picklist values are stored in a semi-colon delimited string that is split into multiple values when the workflow rule does its evaluation.

I've done some testing and the results I'm seeing are different than what I was expecting, and the documentation doesn't make it very clear. So here we go:

Working Scenario - "Includes"

From the documentation linked above:

Available when you choose a multi-select picklist as the selected field. Use this operator to find records that include one or more of the values you enter.

There exists a custom multi-select picklist field (Custom_Picklist__c) on the Lead with the values: A, B, C, D.

There exists a custom checkbox field (Checkbox__c) on the Lead.

We create a Workflow rule that sets the Checkbox__c field to true every time a lead is created or edited and Custom_Picklist__c includes A, C

Results:

Lead #1: Custom_Picklist__c = null & Checkbox__c = false

Lead #2: Custom_Picklist__c = B & Checkbox__c = false

Lead #3: Custom_Picklist__c = A & Checkbox__c = true

Lead #4: Custom_Picklist__c = A; B; C & Checkbox__c = true

All results evaluate as expected. The record only needs one of the values to be selected in order for the workflow to fire.

Broken(?) Scenario - "Excludes"

From the documentation linked above:

Available when you choose a multi-select picklist as the selected field. Use this operator to find records that do not contain any values that match the ones entered.

Same as above - Custom_Picklist__c & Checkbox__c custom fields exist on the Lead.

We create a Workflow rule that sets the Checkbox__c field to true every time a lead is created or edited and Custom_Picklist__c excludes A, C

Results:

Lead #1: Custom_Picklist__c = null & Checkbox__c = true

Lead #2: Custom_Picklist__c = B & Checkbox__c = true

Lead #3: Custom_Picklist__c = A & Checkbox__c = true

Lead #4: Custom_Picklist__c = A; B; C & Checkbox__c = false

Results do not evaluate as expected. I did not expect to see Lead #3's checkbox field set to true. The workflow rule is set to only act on records where the multi-select excludes A, C - I expected that to mean that the record would be ignored even if only one of those values is selected.

Am I misunderstanding the documentation? Or did I find a workflow bug?

---

Edit: I did some more testing using multi-select picklists with "equals" and "not equal to" and so I wanted to share those results as well.

Working Scenario - "Equals"

Same as above - Custom_Picklist__c & Checkbox__c custom fields exist on the Lead.

We create a Workflow rule that sets the Checkbox__c field to true every time a lead is created or edited and Custom_Picklist__c equals A, C

Results:

Lead #1: Custom_Picklist__c = null & Checkbox__c = false

Lead #2: Custom_Picklist__c = B & Checkbox__c = false

Lead #3: Custom_Picklist__c = A & Checkbox__c = true

Lead #4: Custom_Picklist__c = A; B; C & Checkbox__c = false

Results are as expected, I guess. The "equals" operator is different than "includes" because Lead #4 evaluates to false. The picklist must equal A, C (or just A or just C) and cannot contain another other values.

Broken(?) Scenario - "Not Equal To"

Same as above - Custom_Picklist__c & Checkbox__c custom fields exist on the Lead.

We create a Workflow rule that sets the Checkbox__c field to true every time a lead is created or edited and Custom_Picklist__c not equal to A, C

Results:

Lead #1: Custom_Picklist__c = null & Checkbox__c = true

Lead #2: Custom_Picklist__c = B & Checkbox__c = true

Lead #3: Custom_Picklist__c = A & Checkbox__c = false

Lead #4: Custom_Picklist__c = A; B; C & Checkbox__c = true

Lead #5: Custom_Picklist__c = A; C & Checkbox__c = true

This one blew my mind and I had to include even more results here because it's just damn confusing. If the picklist only has A selected or only has C selected, the workflow works as expected. I can maybe understand why it evaluates to true if A, B, and C are selected since B is not part of the not equal to criteria.

But A, C evaluates to true? How? Those are specifically the values I'm setting the criteria for not equal to.

Answer 1

Salesforce's response to this issue (Case #15237638) is as follows:

The multi-select picklist scenarios above are working as designed. They have submitted my feedback to the Knowledge team to update the documentation (as while it may be working as designed, I argued that it is certainly not working as documented).

The following workaround can be taken to achieve better results:

Wherever an 'AND' comparison is intended, the multi-pick list values should have their own lines in the criteria. Ex: If the workflow is intended to fire when both A & C are excluded, A & C should be in separate lines.

(I think they meant to say 'OR' comparison here, but I'm not entirely sure.)

I created an idea to hopefully gather upvotes in improving this feature - so if you feel this needs more attention, I would appreciate an upvote: https://success.salesforce.com/ideaView?id=0873A000000cNJdQAM