Hi,
As per standard, system calculate the PR qty based on your input."Child part1" is used in both of your header material with 1 to 1 ratio, so based on your header materials (A,B) requirement (100+200) and additionaly safety stock as 100, totally PR generated 400 qty."Child part 2" which is used in your header material with 1 to 1 ratio, based on material "A" requirement, it will create PR 100 since you didn't maintain any safety stock/scrap qty. But for child part1, system should be generate 430 inclusive of scrap %. For that check your scrap % value in material master as well as header material's BOM.
It's really not understandable how system will generate PR for your child part 2 as 50 qty as you mentioned in your expected output. Check the BOM ratio of header vs component.Generally system will propose the PR/Planned order based on requirement as well as maintained input values at master level like material master, bom etc.,
Thanks
