Scrap vs. DMR

We are a repair shop that receives customer parts that we restore to
original condition. We receive the part into inventory and treat it
as a material to the job.

Occasionally a part will be deemed unrepairable during the job and
needs to be scrapped out. We would have to adjust the qty on the
order to the repaired parts and invoice for the qty minus any scrap.
The scraped part is than either disposed by us or shipped back to the
customer upon their discretion.

My question is whether we should use the scrap qty at the operation
level or do a DMR rejection? My main concern is where the costs will
go if I scrap the parts by using the scrap qty. Would it go to the
same place DMR rejections go? I would appreciate any help concerning
this manner.

Thanks in advance,

Jason