Where to input processing time on a work definition?

Our business does not currently use Supply Planning, Order Promising or Sales and Operations Planning.

They create work orders manually when ready to make an item. The planning of what to make, what quantities and when are currently determined outside of Oracle.

When work orders are created manually both the start and completion dates auto populate to be the exact same date and time. Our users are manually updating the completion date with their actual estimated completion date

The fields in PIM for processing times on make items do not do anything without planning processes to ingest them and generate work orders from requisitions