Weldment Drawings, BOM and Cut List

Things could be worse: You could have a program that pretends to do that but really screws up.

It's been a while since I worked with SolidWorks (I'm on Inventor right now) If I can' recall, if this would apply anymore... What I've experience and still experiencing, is that when you initially set up your standardization is to create it initially for generating an actually cut sheet.

Too many managers are taking what they learned in the class room, not realizing what they teach is an example and that you can customize it to your organizations requirements.

I quote: "Too many managers are taking what they learned in the class room, not realizing what they teach is an example and that you can customize it to your organizations requirements."

No, too many managers take the crap they learned in school to heart, and never investigated anything further on their own.

My tongue seems to have sharpened this week, but my shoulder and neck are paining me now, so I have a good excuse.

Easy with that sharp tongue, if you're not careful, you'll put your eye out with that. I haven't a problem with that, because I'm wearing my safety sunglasses.

Seems like you are mixing up materials procurement and pre-assembly requirements....

http://help.solidworks.com/2016/English/SolidWorks/sldworks/c_Materials_in_Weldment_Cut_Lists_weld.htm

Weldment bill of materials

https://www.3dvision.com/blog/entry/2014/03/26/weldments-and-bill-of-materials.html

I seem to be trying to do things differently from SolidWorks but I see it as the opposite of mixing up materials procurement and pre-assembly requirements.

I'm trying to put a materials procurement table (traditional BOM) on sheet 1. If n items of different lengths get cut from one single piece of X by Y steel then the procurement BOM would have one line entry with the total requirements of X by Y steel. Clean communication with Procurement.

Page 2 would have the cut list. It would collect and summarize the list of pieces (possibly many) that may have had cut instructions on several different sheets. Each unique length would be in a new row. This list could be much longer than the BOM list. The cut list would have item numbers or the equivalent of item numbers that would identify cut pieces in the overall weldment. Clean communication with Manufacturing.

Having "item numbers" in a BOM and "item numbers" in a cut list could cause confusion.

I'm starting to conclude that no one does it this way. It appears that only cut lists appear on weldment drawings and Purchasing has to add up all the cut lengths to calculate a total requirement.

Just checking to see if anyone has a better way.

It only makes sense to have the cut list as a subset of the BOM list, this allows for cross checking materials....or you can make each item of material and it's cut menu a separate file with 2 sections material spec and cut list with a separate file for totals...maybe it would help to draw a diagram, then adapt it to a program...

http://www.resource-lab.de/documents/flow_management.pdf

I've done what you want in Inventor. I'd be really surprised it Soldworks doesn't have equivalent facilities.

In the drawing BOM to be released to the shops I had the normal list of finished weldment items with callout balloons.

On a separate sheet at the end of the drawing package I would use programmable tallying equations (provided in the software) to generate a procurement list of the individual shapes that had been rolled up into quantities based on lengths that were most efficient and/or required by the buyers; ie, X amount of 6' or 8' lengths of 1x1 angled aluminum, for example.

This procurement list was pretty informal and was designed so that it could be transmitted via paper, text file or spreadsheet depending on the ever changing purchasing requirements. I had also designed the output to be friendly to automated transmission to the companies ERP system should they eventually get to that stage. They hadn't as of when I retired.

Lastly, the shops never saw the rolled up procurement list as they had no need or interest in it. For aviation quality requirements the raw uncut materials were usually delivered to the shops per the individual job needs and no substitutions or variances were allowed without formal engineering approval.

Hooker

I probably won't get a chance to hit this again for a couple of weeks. Having a cut list on the drawing seems to be what I will end up doing.

After thinking about other responses I am looking at my goal a little differently. I have worked at a couple of companies that listed the total actual material consumed on the BOM. They then used a "fudge factor" such as 1.3 for procurement and costing. This worked well BUT for them a large item was a 19 inch rack mount chassis. The biggest items cut were a small fraction of the 4' x 12' sheet of purchased aluminum.

What I have gotten used to is a special case environment and not appropriate when large portions of the purchased material is used.

If we are using a turret punch to cut a hundred items of various shapes out of a 4' x 12' sheet of aluminum then what I have been doing still seems like a good idea. Somewhere around 0.1 of an item and it starts to look less like a good idea. Up around 0.25 of an item and it starts to look like a bad idea. I guess that is part of my answer even though that is not a part I was looking for.

I think I understand what you are trying to accomplish but I can see two problems with it immediately. First is, what happens when your 'purchase BOM' automatically adds up all the individual lengths of a certain type of tubing for example and the result is 85' feet of tubing? I suppose you could program your BOM to limit 20' maximum length. But this relates to the second problem I see which is what if your supplier doesn't have 20' lengths but they do have a bunch of drop-cuts that meet the requirements of your job but the purchaser would not realize that because all they know is that they need a total of 85'

Nonsense. You COULD get an 85' length of tubing.

The shipping charges might be cause for a an additional conversation and clarification.

Are you suggesting that a BOM material length of 85' is somehow ordered and delivered without any checks?

A competent designer would know what lengths are available before releasing the BOM.

A competent purchasing person would know this also prior to placing the order.

A competent supplier would never ship this, even if possible, without confirmation.

Where I worked I consulted with our purchasing department to find out what data formats they would accept with the least muss and fuss in the engineering design process, and that would give them the most used material configurations. It became totally unnecessary for our designers to worry about purchasing details like stock lengths, and the cad system generated the BOM's and cut lists without their input.

When they analyzed the purchasing needs they consulted with the shop floor expediters to see if it would be beneficial to use anything currently in stock. We tried very hard to not stock excesses. Storage is expensive (per sq ft) and handling the same material multiple times is expensive. Purchasing was also responsible, of course, for lasting relationships with our vendors as we were actually relying on our material vendors to be our stockrooms with quick turnaround service.

No one department can unilaterally determine what the best data formats and processes are for the company in anything much larger than a mom and pop operation. We strove to use the intelligence of our engineering design systems and ERP to minimize paper and eliminate multiple data entry errors. Unfortunately, nothing off-the-shelf will usually work unless you restructure to fit. It's easier to meet in the middle by modifying software and tweaking the work processes to fit the modified software.

Was it perfect? No. Were there exceptions? Absolutely, but we continuously refined to try to minimize costs.

Hooker

One could get a 96" x 240" sheet but who the hell would do that if your not equipment for it or need to wait for it.

you try to configure your cad specs on the output to your capabilities.

the problem I had run into is, I work with lengths (pipes, tubes, structural components) which works great for cut sheets and for the other sq. Footage. (For sheet metal and plate) at least most times. AP/AR using pounds.

Yes you can get just about any length you want in any material, as long as you are willing to wait and pay any extra charges to get it. It is common to do this if you have enough volume - you will likely just have to wait for the end of the "rolling" to get your size(s).

The BOM (or cut list) I have found over my many years is best listed as every separate piece, even pieces the same size but with different hole patterns, etc., are assigned different "item" or "detail" numbers. This allows the fabrication department to group similar items that may have a first common fab step, but different steps that follow.

Purchasing has a job to do just like everyone else and if "competent" they should be aware of what is available or be able to find out what is available. So let them do their job accordingly. If they have issues or suggestions, they can always consult with the designer, or the fab shop or both to see if there can be logical substitutions or changes in design that will let them do their job competently by reducing the input costs of the item(s) made without affecting the quality.