Phantom BOMs


(Calvin Krusen) #1

Is it possible to make a Phantom BOM for a “sub-assembly”, so that its components are pulled during Mass Issue, without having to make a sub-assy in the Job?

We have products that use varying amounts of different Epoxies - each epoxy consists of two components (the resin and the hardener). The different mixtures may require different mixing ratios (1:1, 2:1, etc…), and the final volume may vary (some expand more than others).

I’d like to make a Phantom part for the mixture, with a BOM calling out the proper ratio of the two parts. I’d also like the UOM for the phantom part to be in some unit of volume, so the engineer needs only enter how much volume they need to fill, and not to have to figure out the cured density and mixing ratio for every two part epoxy we use.

Sample Indented MOM for finished product WIDGET-001:

MTL#    PartNum    Description              Qty UOM  Fixed
10      WID-CAN    Canister for Widget-001    1  EA    NO
20      WID-GUTS   Internals of Widget-001    1  EA    NO
30      EPX-0001   Epoxy Blend XYZ-123      125  CC    NO

The BOM for EPX-0001 would be:

MTL#    PartNum    Description               Qty    UOM  Fixed
10      EPXR-001   Resin, XYZ-123           0.0200  LB    NO
20      EPXH-001   Hardener, XYZ-123        0.0125  LB    NO

EPX-0001

  • Would not be stocked, and would have UOM of CC
  • has a mixing ratio of 2:1 by volume, which equates to 2:1.25 by mass
  • 0.02 LB of Resin + 0.0125 LB of Hardener yields 1 CC of cured epoxy.

Currently, that first MOM would be:

MTL#    PartNum    Description              Qty    UOM  Fixed
10      WID-CAN    Canister for Widget-001   1      EA    NO
20      WID-GUTS   Internals of Widget-001   1      EA    NO
30      EPXR-001   Resin, XYZ-123            2.5    LB    NO
40      EPXH-001   Hardener, XYZ-123         1.5625 LB    NO

Which is a pain to calc the required raw material of each epoxy component, for each job.

Thoughts?


(Brandon Anderson) #2

Yes you can make a phantom for a sub-assembly. One the part master for the assembly (epoxy mixture), you need to check the phantom bom and in the site tab check phantom bom. Make sure you check both, as the system doesn’t check the site tab on for you. (we found that out the hard way). Then in engineering workbench, it’s pull and plan as assembly. On the job it will pull the materials and operations up a level, and should multiply the quantities accordingly. Make sure you double check that though as we have had problems in the past with it. It should be fixed, but I think there are still some goofy things with scrap rates if you try to use those.

It should work. We’ve used some phantom bom’s here, mostly to try to reduce the number of travelers, but we needed prints anyways so it got confusing for the shop and so we went away from phantom boms mostly. But for your use case, I think it would work well.


(Calvin Krusen) #3

I’ll have to give the way to handle scrap a lot of thought. Epoxy mixtures always have scrap.
Ideally it would just be the qty stuck on the sides of the mixing container. But that varies (non-linearly) with the qty you’re mixing. The non-linearity is dependent on the mixinig container size.


(Brandon Anderson) #4

You can still issue scrap as desired, or issue manually if you don’t backflush. It’s the backflushing that was giving someone on here problems with scrap rates.

How do you handle it now?


(Calvin Krusen) #5

Very Poorly … :frowning:

The qty used in our products doesn’t need to be real exact.
Engineering determines how much cured epoxy is in the final assy, and calculates the exact qtys of the resin and hardener to use - occasionally making errors (mixing ratios, LB to CC conversions, etc…)
The shop people know the mixing ratios of the various epoxies, and pretty much eye ball how much they’ll need - making a little extra to make sure they have enough.

So nearly every mass issue is short (doesn’t include any scrap). Which constantly leads to to QOH errors.

The simple solution is probably to just keep what we are doing, and do frequent cycle counts of the epoxy components. But accounting wants scrap to be assigned to specific jobs.

I guess adding some level of scrap (no matter how accurate) to the jobs, would reduce the total scrapped during cycle counts.


(Matrix) #6

Only just seen this thread sorry guys. We manufacture some of our products using Epoxy and other chemicals and often use phantom BOM’s on lower level assy’s. We have a part master BOM for 1kg of the parent mixture (Epoxy plus catalyst etc…). Whoever is setting up the job simply uses the theoretical injection weight on the top level part qty within the method of the part being manufactured or in the job if it’s getting detailed on the fly. Then using get details the system will multiply the theoretical weight in kg of the parent x the child ratios which will then collapse as seperate child parts within the job.
As Brandon rightly pointed out though, something odd can happen with the scrap values. We, like you guys don’t have a linear scrap factor, our scrap is based on the size of the injection hose so it doesn’t matter if we fill a mould with 1000L of mix or 200L of mix we still only require say 20kg of scrap.
In Vantage (before we upgraded to E10), would could detail say 1000kg plus a fixed scrap qty of 20kg as a parent part. When using get details in the job you would see each of the child quantities multiplied by 1020kg.
In E10, the system multiplies the child parts by 1000kg then shows 20kg fixed scrap in each of the child parts which to put it bluntly is a pile of bollocks and totally goes against any logic whatsoever. The only way we can get around this is to use a theoretical qty of the parent mix part number with zero scrap, then add a 2nd parent mix part number using the 20kg with zero scrap. It’s not the most efficient way of doing it but at least it gives us the correct backflushing of the materials.
Anyway, I hope this is of some benefit and if you ended up fixing it please share your ideas.
Cheers,
Rob


(James McKinnon) #7

Could you have this backflush to a fictitious non-nettable location for the job consumption, but actually issue in full unitary measures from you stores. The delta between the backflushed consumption and what you have issued is your scrap and your system on- hand is full containers only - your production folks need to manage open containers off system.


(Calvin Krusen) #8

Just to be clear, When I say scrap, i mean the extra material required to complete the job. We’re not trying to account for the “scrap” to a GL account. We just want the QOH’s to be accurate after the material is physically issued. I guess the extra material required should be called “waste”, as we still want the costs of it to go to the Job and not a scrap account.


(James McKinnon) #9

Same principle, the delta between the full unitary issue and the consumption is your waste - essentially what you planned to use versus actual. Ultimately your on hand quantity will be correct.