Validation rule to prevent change of case owner to queue

Question

I need to create a validation rule in order to prevent users with TS value in picklist Service field to update the case owner to a specific queue, so basically if current owner has TS in service field he should not be able to change the owner to one queue. This validation rule should not affect system admins.

This is what I currently have:

AND(
    ISCHANGED(OwnerId),
    ISPICKVAL(Owner:User.Service_Level, "TS"),
    Owner:Queue.QueueName == "3 Level"
)

However it does not prevent users from changing the owner to this queue. Can anyone help with this?

Answer 1

You have created a Validation Rule whose criteria can never be satisfied. Because you use AND, each subcondition must be met. But you have two mutually incompatible subconditions, because the second requires the new owner to be a User, while the third requires it to be a Queue. You need to check the previous owner for TS, not the new owner.