@Marco Casavecchia, I noticed your question the other day, and it got me thinking.
I built a model a couple of years back using a custom made MRP algorithm to control production in a fluid processing plant. It took us quite a while to get it right, but it turned out very well.
The model did a daily recalculation based on stock, sales forecast, actual sales, BOM (Multiple levels), and WIP, and the result was the daily production orders, packaging orders and raw material orders.
I have never since had the opportunity to expand and improve on this logic, but it looks like it may happen soon.
I am curious - has anyone used MRP calculations in-model and was it a success?
Best regards
Christian
---PS---
Material Requirements Planning is a way to control production based on product portfolio, demand forecast, bill of material (~recipes), stock, lead times and a lot of other information. It results in a set of demand quantities on all levels of BOM.