How to handle job material qty required based on total to be made

We have some materials that we can make 30 pieces out of it. but if we make 31 then we would need a 2nd qty of that material.
It isn’t really a fixed quantity. but I don’t want to say it is 1/30th per parent. because if we make 29 it is 1/29th per parent.

How have others handled it?

I would specify the lowest quantity per piece as the BOM quantity. For example, if you get 30 pieces per blank, but occasionally (due to whatever reason) you only get 29, the material callout would be .0345.

At least that way, you’ll never run short, but might have the occasional extra piece if you yield 30.

The alternative is to call out your raw material dimensionally. If you have a bar that is 12 feet long, and each piece is .0345 of that, the BOM would be .414 feet of material per piece. Your unit of measure of the raw material should correspond to the same unit of measure you specify in your BOM callouts.

This gets to be “fun” in the sheet metal world.

Is the unused portion of the material (the component) unusable and therefore always scrapped?

Like if a job was to make 25, would the leftover portion (the qty that could have made 5 more) scrapped?

You could make the Qty per to be “fixed” (independent of the Job Qty), adjusting it to be a the ceiling (a function that “rounds up”) of the real qty Per * Job Qty.

Thanks guys for the additional questions.
The business case is specifically Master cartons and skids.
When we make a part we can get 30 in a master carton.
And we stack 300 (10 master cartons) on a skid.
Our mfg multiple is 30. Our min is 30. We can’t consume .0345 of a master carton. And we can’t consume .1 of a skid.
So when we get an order for 600 pieces we need to know that we need 20 master cartons and 2 skids.
Anyone solve that type of material requirement?

And what if you get an order for 500 pc’s? Not take it? Force the customer to buy 600?

We would build 500. That would use 2 skids (more than 300) and 17 master packs.

Would you sell 500?

Or sell 1 Skid + 6 Master Cartons, + 20 Individual pieces?
(1x300 + 6x30 + 20 = 500)

So… there is a trick that I always like to show…

  1. Each UOM should NEVER allow decimals (by definition… Each is qty 1… never have .25 each)
  2. BUT… even if the material is in EACH, you can still specify that you need 1/30 of an each in the BOM. YES, this is ALLOWED in the BOM…
  3. but when MRP runs, and creates the job… it will calculate how many EACH of the material you need to issue to the job automatically
    SO… if using the above rules/technique, if you have a job for 29 pieces, it will say to consume 1 material, but if your job is for 31 pieces, it will consume 2 of the material.
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BRILLIANT! Worst case, make a new UOM of PC (for piece), with no decimals.

BTW - if one ever plans to use serial numbers, you need a UOM with zero decimals.

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Ok so we were doing this already. It just seems so strange.
Thanks everyone for talking through this.