bill of material

[cad4sb]

When we initially release an assembly drawing, the bill of material (table-based Bill of Material) generated in solidworks is used by manufacturing as the item master used throughout the company.
Do you know what other companies are doing to control the integrity of the bill of materials?

 

[MadMango]

At my last job, the BoM was not on the drawing, but was input into our ERP system. At my current job, the BoM on the drawing is "for reference only" and the BoM that drives production is maintained in a separate, non-associative Excel sheet.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[JMirisola]

One would think that, assuming engineering is doing their job, that the BOM on the drawing would be the correct one and should be driving the ERP system. All too often I've seen deviations, because a buyer or production manager made assumptions about one part or another, that caused problems down the road. i.e. "We can use this 1/2-16 bolt here, it'll work just fine." Except, it was supposed to be a Gr.8 bolt and they used Gr.5.

My point? Engineering should drive the BOM, and the drawing is the perfect vehicle.

Jeff Mirisola, CSWP
Certified DriveWorks AE

http://designsmarter.typepad.com/jeffs_blog

Dell M90, Core2 Duo
4GB RAM
Nvidia 3500M

 

[gurujeff33]

ERP or MRP system usually drives the BOM, with SW BOM a secondary device. You can get fancy and get PDM system that also manages BOM's and takes the input from the SW assy to create the BOM's.

 

[ctopher]

I agree Jeff. Engineering should drive BOM's.

Chris
SolidWorks/PDMWorks 08 2.0
AutoCAD 06/08
ctopher's home (updated 10-07-07)

 

[CADFlyer]

In a perfect world, engineers should control everything!

 

[JMirisola]

gurujeff33,
If the product is designed by engineering, it should be the BOMs that drive the ERP/MRP system. When purchasing or production make changes, innocuous as they may seem, bad things can happen. I know of what instances where production did exactly what I mentioned in my previous post; used non-structural bolts in a structurally critical area. This resulted in tens of thousands of dollars in lost hours and recalls.

Jeff Mirisola, CSWP
Certified DriveWorks AE

http://designsmarter.typepad.com/jeffs_blog

Dell M90, Core2 Duo
4GB RAM
Nvidia 3500M

 

[gurujeff33]

JMirisola, I agree with you. The SW BOM needs to drive what changes are done on the MRP BOM. In a perfect world they would be linked. Some Engrs just make the change to the SW BOM and expect MFG to change MRP boms or some people do both at the same time. None the less there are usually 2 boms and the MRP shouldn't drive the SW.

If you have purchasing and other folks that are able to make a BOM change substituting a different part number for a lower grade bolt then you have something wrong with your change process. Engineering should be on the loop for the process and sign off on a change like that. If they just substituted lower grade bolts for the same part number then there is either a purchasing/mfg problem with reading a spec/drawing or there is a problem with the spec/drawing.

Either way those are both big no/nos and should be immediately corrected

 

[MadMango]

Those types of things should be caught in your ECO/ECN processes, but I know that doesn't always happen. We had a problem at my last job, where SST components were changed to power-coated mild steel for savings. It didn't save anything.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?