Bom - pcs to lf

I’d like to setup a part that will be in LF put consumes PCs of another part. For example, I have a master roll that is 12 inches wide (MR). It will be consider a PC. I slit 3 inches from this roll, which I will now inventory in FT (SR). The difficulty is the master roll is not always a consistent length. I was hoping I could use a fixed quantity in the SR BOM so in this example it would always pull .25 pcs of the MR. This works, except we will often want to slit an entire 12 inch roll into 4 SRs and with this setup I’d have to create 4 jobs to do so, since the fixed quantity is set to .25 pcs. Any thoughts?

I’m having trouble with the acronymns, but have you looked at the UOMs per Part?

Yes I have. The acronyms are really just my identifiers for the example. MR - Master Roll, which is in the BOM of the Slit Roll (SR).

Do you sell the MR? Or only use it? Are the SR always 3 inches? Or do you have varying sizes?

Only use the MR. The slit rolls (SRs) can be in varying sizes and therefore consume differing quantities of MRs.

I’m guessing the MR is not lot tracked?

Preferably it would be.

A couple of questions because I’m not quite understanding the process.

  1. How are you changing the MR to the SR?
  2. When you are cutting, you are cutting a variable length x 12" width?
  3. What would be a nominal length for a MR?
  1. MR is being converted to SR with a job.

  2. Yes, and it is that variable length that is causing the math issues.

  3. Typical length would be 50 LF.

A few questions, just to make sure I understand…
You could have 12" wide master rolls of varying lengths in inventory…
and multiple demands exist for varying lengths of master roll(s)?

three 12" wide master rolls in stock of various lengths, e.g. 15" 24" & 36" long
( where the system would report 75" in inventory )?

Is the “math problem” turning into manual intervention in the shop… where someone has to manually check master rolls to know which are really useable for specific demands?
e.g. if a job to make qty 4 of 12" wide x 4" long, then one of the master rolls in stock would be too short for the whole job? (15" partial master roll in the example above)?

So “yes’ to everything you state. However, our plan was to have the master roll in “PCs” because the 12” wide roll could have a 1" wide roll taken from it or a 6" wide roll taken from it. In these examples, the slit roll would consume either .1 or .5 of the master roll. This would allow visibility of what width of the master roll we have on hand. The difficulty is, how do we get the master roll, in PCs, to align with the LF of the slit roll if the actual length of the master fluctuates.

Then this sounds like something a fairly common problem discussed on multiple threads.
Unfortunately I have never heard of a way to do everything automatically. but I’d definitely like to be proven wrong on this.

Some links I could find…

and I remember another thread but could not find that one
It explored different ways to store/track the raw material. Unique part numbers/lots for “partials”… where the potential problem was ending up with a LOT of part/lot numbers to keep track of the raw material.

Thanks Bruce. I’ll certainly take a look at these.