OPM and ASCP

Hi

We have requirement to plan raw material in terms of demand of piece parts.

eg. Raw material(ingreiant) is a cattle/sheep

piece parts are

Legs ,  body parts.

Now if the demand is varying based on above parts that is if the legs have demand of 100 and body parts of demand 50, then in this case how can I plan for the  raw material. Is there any constraints or modifiers used.

Since if the demand of one part outstrips the other parts, i need to plan effective raw material where it does not get wasted since other parts demad is low compared to legs.