when do we see "Material Rate Variance" for a work order closure journal entries

Hi All,

We are having a situation, we are on contract manufcaturing process. On work order operation one item is assembly pull and one item is push. The item which is having as assembly pull is a service item. So whenever we complete the operation for another item having push, the pull item will get auto received on PO.

(in Contract manufcaturing we have work order, req and PO would get auto generated as we know the process - Here the PO and req gets generated for service item)

On PO the service item is having 10$. But as per the cost management item's unit cost is 12$.