Overall Yeld on planned orders

Good Evening everyone,

I am looking for a way to take into account production yeld on planned quantities in SAP for a manufacturing process with multilevel BOMs.

MRP1 view contains the % of assembly scrap, which is useful to let MRP generate planned orders with a quantity that is calculated as the sum of forecasted scrap and requirements (eg we have a requirement of 100 ea and production generates a 1% scrap: MRP run generates a planned order for 101 ea, 100 available and 1 scrapped).

yeld can also be defined as the forecasted production loss that i will get from a process, and for stable productions which can be repeated it is a well known datum, so I was wondering if there is any way for SAP to do the scrap calculation starting not from the available quantity required, but from the available quantity that I will get if I produce the exact required quantity; based on the example above, MRP should generate a planned order for 100 ea, but on MD04 only 99 will appear as available in MD04. Obviously this kind of rule will work with a certain tolerance on requirements....

thanks in advance for each single suggestion

B