Workflow should check and wait if GR is not done

Hi Experts,

I have a Requirement that.. If the Purchase order is not done with the GR then it should wait for 15 days if between this 15 days if the GR is done then the workflow should process and call MIRO Transaction.If the GR is not done for 15 days the an escalation mail should send to user.

i have Done this using loop and used deadline monitoring for one day...but users suggested to look other solution rather then using Loop.

so please help me on this

Thanks,

Charan Tej