Why Can't I Assign an Approval Step to a Queue for a Custom Object Approval Process?

Question

I know that when running an approval process on Case, you have the option to assign an approval step to a Queue, however, I am now creating an approval process for a custom object, and I don't see the option to 'Assign to a Queue'. Does anyone know why or if it is possible to assign an approval step on a custom object to a Queue?

Thanks!

EDIT: As it turns out, the custom object that I wanted to use a queue for is a child in a master-detail relationship, which does not technically have an owner, and can therefore not use queues.

Answer 1

If the object you are working on is a the detail of a Master-Detail then you cannot have a queue for it. From the documentation:

The Owner field on the detail and subdetail records is not available and is automatically set to the owner of the master record. Custom objects on the “detail” side of a master-detail relationship can't have sharing rules, manual sharing, or queues, as these require the Owner field.

Answer 2

I believe you would need to create a Queue for that Custom Object, before it becomes available to assign to. (A Case Queue must exist straight off the bat, which is why you wouldn't have had to create one) http://login.salesforce.com/help/doc/en/setting_up_queues.htm

Answer 3

You can assign approvals on a detail object to queues, but only if you create a queue that can own the master object. This may not be possible if the master object cannot be owned by a queue.

These approval processes on the detail object that reference queues for the master object cannot be deployed via the metadata API, but can be created/modified through the standard UI. (you can deploy them with the assignment to a named user, and then switch it to the queue through the UI).

I've also heard of people working around the issue in the following way:

1. Creating the detail object without the master detail relationship
2. Creating queues for that object
3. Creating the approval process with the queues referenced
4. Adding the master detail relationship to the object.

You may want to try this, but it could be that it is no longer possible or unsupported by salesforce, it's certainly an ugly workaround.