How does Make to Stock unfirm job created by MRP calculate due date?

I am confused as to how Epicor is coming up with a due date on an unfirm job that it’s creating via MRP.

I’ve created a very simple part with a BOM that contains:

  • A subcontract operation with 14 days out on the operation.
  • One material related to the subcontract operation. The material is non-stock and has a 10 day lead time.

We’ve set the inventory min/max on the finished good part so there is not enough in inventory now, and ran MRP for that part. I would expect it would set the due date on the job out about 24 days (10 days to get the material in per the lead time, and then 14 days to perform the subcontract operation). There may be a little wiggle for receive time, etc.

It appears to have correctly set the purchase suggestion out 10 days. However, it’s not accounting for the lead time when setting the due date on the job. Basically, it’s setting the job to start now, it will cal for the material as soon as it starts.

What is causing the Job Required By date to get set initially? Is there some way to get that to reflect a later start if there is not inventory on hand for the raw material?

Kevin Simon

Trying using constrained material

MRP suggests ‘Required By Date’ and thereby Job Due Date for jobs based on the pegging processes, and your part and demand setting, i have counted about 14 factors, i am sure there are more:

  1. demand need by date…on sales order
  2. demand firm status…on sales order.
  3. Min on hand…on part maintenance.
  4. days of supply and receive time…on part maintenance.
  5. Process MRP…on part maintenance.
  6. Part Type…Manufactured or Purchased… on part maintenance.
  7. Material lead time or lower level Job due date of using material constrains.
  8. Operation Time and Sub./Cont. days out…on Part Rev. copied to JobOper.
  9. Current Part on Stock.
  10. Resource/Resource group setting, include Move time and queue Time between operations.
  11. Type of scheduling (Finite or Infinite).
  12. Company Calendar and Planning Configuration.
  13. Site Production/Planning Configuration.
    14.Supplier Calendar if used.

i believe mrp considers any below MIN/below SS requirement immediate and creates jobs accordingly as such