To modify the fields on the target object from Q-assign to use it for reporting or any other purposes, you simply need to create an action rule on the Assignment Group without adding users for assignment. To do so, please follow the instructions given below:

Note: Do not add any Users/Queues to that Assignment Group, neither any Matching Rules, Member Point Scoring Rules or Active Record Criteria. Similarly, there's no need to define assignment related specifications such as Member Availability settings or Assignment Schedule settings.
Please keep in mind that this Assignment Group will only update the record fields which will be modified by defined actions, i.e. Q-assign Last Assigned Data, Q-assign Assigned From Group and other Q-assign fields on the records will not be updated unless actions modify them. So if you want to stamp any field just for reporting or knowing when records have been modified by this Assignment Group, you will have to create an action rule for that and specify which field to update.
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