In an order related product structure, once the work order is created, if you change the quantity to be produced on a lower level assembly the full quantity will be reserved to the higher level with no immediate impact on the residual stock and the subsequent MRP calculation.

First we define the item structure with one subassembly. Both items father and child are set as order related on item master data.

We have a simple Item Structure like the following

Now we create a sales order for the father item PMJAMES and from the sales order we create  the  work order

Now on the subassembly work order position we will change the quantity to be produced. We will double it as an example

Then we run the MRP calculation

These changes will not be considered on the order recommendation as beas assumes that any excess production for the lower level assembly will be reserved for the higher level product and therefore will not be available in stock.

Lets see the result of the MRP calculation for the subassembly Zhiliangtest

The result will be the same when you receive the subassembly Zhiliangtest on your work order. The only exception will be in the reserved quantity column where you will see the total of 20 pieces reserved for the higher level position.

Suggestions

1) If you are going to produce excess quantity of the sub assemblies, set the item master data as stock related. This is the correct usage of beas. You should not change the quantity of the sub assemblies position on an order related structure

2) Choose one of the following options:

- Create the orders for the subassemblies as SEPARATE stock related orders and when the quantities are received into stock reserve them on the higher level of the production order corresponding material position

- Set the subassembly position on the Extended TAB of the BOM of the higher level product as .

This will generate the sub assembly order related work order position ONLY for the quantity that is currently not available in stock at the time you create the work order for the higher level product