MRP, and what it means for formulas

MRP stands for material requirements planning. Behind the acronym is one calculation: take what you plan to make, break it down into everything it needs, subtract what you already have, and you are left with what to buy and when. Classic MRP was built for assembly, where the breakdown is a parts list. The same calculation is exactly what a maker working from recipes needs, with formulas in place of parts lists.

The calculation, in recipe terms

Explode. A planned 20 L batch of sauce needs 14 kg of fermented mash. The mash is itself a formula, so it explodes again into habaneros, salt and water. Sub-formulas mean the breakdown is a tree, not a list.

Net. Against that requirement, subtract what is available now, which is released stock minus whatever is held or reserved for something else. See availability.

Time it. A shortfall matters only if it arrives late. Each vendor has a lead time, so the useful output is not “you are short 4 kg of salt” but “order salt from this vendor by Thursday”.

What makes formulas harder than parts

• Yield. You need more input than output, at a rate learned from real batches. Plan on the recipe alone and you come up short every time. See yield.
• Depth. A sauce made of a mash made of ingredients is two levels before you reach anything you can buy.
• Units. Recipes are in grams, purchases in cases and sacks. Something has to convert between them without rounding you into an extra pallet.
• Shelf life. Ordering early is not free when the ingredient expires.

In BatchDash

The planner holds the week’s batches, and buying reads them together with your restock levels. It explodes each planned run to raw ingredients, nets against available stock, groups the shortfall by vendor with pack sizes and minimum orders honored, and tells you the last day to order from each one. From there it writes draft purchase orders.

That is MRP, without the word appearing anywhere in the interface. The pages that sell it are buying and the planner.