S&OP: Fixed hour resource usage in BOR

Summary

How to define fixed hours resource usage in BOR for Sales and Operations planning

Content

Business Scenario: We are operating in life-sciences industry have business scenario in which the FG items to be produced takes fixed time and does not depend on quantity to be produced. We would like to map the scenario for creating Bill of Resources (BOR) for the Assembly items.
We know Oracle provides the Resource for unit-based usage but that just provides usage in UOM other than Hour (i.e time based). The Unit based Resource usage is still variable and depends on Assembly item to be produced.