Planned orders

Hi,

My name is Karen, I am a new user of AX. I need your help for this problem

I have an article A with sizes, its has three components who have the same size table. For example 1 unit of A size 27  needs componente B size 27, component C size 27 and component D size 27.

I set the LMAT of article A with component by size, but in planning master planned orders are based on size 32, should be in size 27.What happens?

Thanks for your help :)