Purchase Order on Hold using BPM

Hi,

I would like to know how i can put a PO on hold if the PO is sent to DMR ( because of any reason) This needs to be an automated task. This is currently made manually but I was thinking if a BPM could trigger the PO that has discrepant material and put it on hold.Did anyone try something similar.. any idea is welcomed .

Thanks,

Lissette Contreras
KEC
Corona,CA