Can you help improve assembly process?

S

SimpleIsGood

Hello Fellow Quality Geeks,

I work for a company that makes assemblies and guess what? We don't always assemble them correctly! This annoys our customer who often pay a lot of money for these assemblies, and just hate it when they are wrong or late. I'm looking for suggestions for improvement.

1) Specifically, how can I even MEASURE process capability? And,
2) How can I make sure each and every assembly is made to match the print each and every time?

I don't want to say what we make (it's a pretty small industry), but the parts have from 5-50 pieces per assembly, and we usually make them in batches of 5-50 pieces. Many of them are large and expensive.

We certainly want to make our customer happy, but even inspecting the products is tricky because their are enough parts to make inspecting each nut, bolt, bracket and Helicoil on each finished assembly impractical, or at least a huge pain in the assets. On the other hand, each and every piece can be made wrong, put in wrong, cosmetically unacceptable, crooked or missing.

I'm trying to help make things better, but the problem makes me feel like this:

:mad:and like this: :eek:

Customer ask, and I can't blame them, "How could you miss that?"

The only things I've come up with is that we stop and start too much. We run out of parts, stop to help on another project, stop to get more parts (some of them are so big you can't keep 20 of them in the work cell), stop to pack assemblies, stop to unpack parts, stop to help on another project, stop to make a shipment, stop to do a trash run (or the work area overflows with packaging materials). Other than that, I don't know where to start.

Suggestions much appreciated. Thanks.
 

Mark Meer

Trusted Information Resource
Assembly checklist are a valuable tool.
Depending on the scope of your assembly process I'd suggest having "checkpoints" at critical stages, where assembly personnel verify critical features.

And, of course, at the end of the assembly there should be some documented release criteria (checks done on every unit assembled).

What should be on these checklists? Depends (of course!).
What is the nature of the non-conformities reported by your customers? Are they all over the map? ...or are there specific issues that keep cropping up?

It may seem common sense:
1. Determine (list) critical specifications or requirements of your product.
2. Determine (list) the things that customers have complained about in the past (in particular recurring issues).
3. Integrate tests or checks into the assembly process to ensure that the requirements are met and the final products are free of common documented defects.

As far as how to measure process capability?
- Customer feedback (reported product non-conformances)
- How often are in-process assembly checks failing?
- How often do finished product fail final release criteria?
 
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S

SimpleIsGood

Check sheets is a great idea! Thanks. It's so obvious I didn't even think of it. We were thinking maybe having formal control plans, but I think simpler is better. If the check sheet isn't enough, THEN we could start using control plans.
 

Wes Bucey

Prophet of Profit
Hello Fellow Quality Geeks,

I work for a company that makes assemblies and guess what? We don't always assemble them correctly! This annoys our customer who often pay a lot of money for these assemblies, and just hate it when they are wrong or late. I'm looking for suggestions for improvement.

1) Specifically, how can I even MEASURE process capability? And,
2) How can I make sure each and every assembly is made to match the print each and every time?

I don't want to say what we make (it's a pretty small industry), but the parts have from 5-50 pieces per assembly, and we usually make them in batches of 5-50 pieces. Many of them are large and expensive.

We certainly want to make our customer happy, but even inspecting the products is tricky because their are enough parts to make inspecting each nut, bolt, bracket and Helicoil on each finished assembly impractical, or at least a huge pain in the assets. On the other hand, each and every piece can be made wrong, put in wrong, cosmetically unacceptable, crooked or missing.

I'm trying to help make things better, but the problem makes me feel like this:

:mad:and like this: :eek:

Customer ask, and I can't blame them, "How could you miss that?"

The only things I've come up with is that we stop and start too much. We run out of parts, stop to help on another project, stop to get more parts (some of them are so big you can't keep 20 of them in the work cell), stop to pack assemblies, stop to unpack parts, stop to help on another project, stop to make a shipment, stop to do a trash run (or the work area overflows with packaging materials). Other than that, I don't know where to start.

Suggestions much appreciated. Thanks.
Consultants, such as I and many others, usually start with the premise:
Watch and learn!
Often, the low hanging fruit is right there for the detached observer to see. If not, there are myriad error proofing techniques which experienced practitioners can scan through (in their mind's eye) to determine which might be applied to best use.

First and foremost, it should be understood that EVERYTHING about the process should be considered for changing (if the economics of change outweigh the cost of poor quality and potential loss of a contract.)

I've been doing this sort of mistake proofing for clients ranging from Bell & Howell back in 1968 to aerospace companies this year. In every case, the reason I was successful and the client hadn't been up to the point of my involvement was simply that most folks were unable to look at the Big Picture AND the itsy bitsy details simultaneously. In effect, the process of error proofing has its roots in Deming's System of Profound Knowledge (SoPK) - it is important to know how each sub-process functions in relation to every other sub-process.

For example:
If the work area can't accommodate all the pieces of an assembly simultaneously, then the work area may need to be changed. Henry Ford did this when he deployed the assembly line process of manufacture, which Boeing still uses today to assemble giant aircraft. Instead of having one operator put together an entire assembly, the work is done in systematic order, with the proper components in place and ready to assemble as the semi-finished assembly moves to each station.

Of course, sometimes, months of agonized blind alleys can be avoided by hiring an experienced, effective consultant.
 

Mark Meer

Trusted Information Resource
Check sheets is a great idea! Thanks. It's so obvious I didn't even think of it.

:yes: ...I can't recall the details, but I believe it was Boeing that first really sold the simplistic value of checklists.

Prior to the development of pre-flight aviation checklists, there were many issues, and nobody knew what to do about them.
Turns out, they were mostly all due to small pilot oversights.
Enter the pre-flight checklist....

Like, I say, I don't know the details but I pretty sure there are stats on the number of seemingly disparate issues that were resolved through nothing more than a single checklist.

...maybe other Covers are familiar with the history? :read:
 
D

DavidDick

When you don't do the assembly process right, you should not try to find a way to check each and every product in the end, but you should try to find a way to optimize the assembly process.

I assert that you don't make the mistakes on purpose. I guess your problem are the work instructions. Bad work instructions, bad results, that's the way it is.

Check out youtube and search for the film "Die leanwork STATION - ein Handarbeitsplatz f?r die Industrie 4.0". Watch it!

It's in German, but I guess the pictures should be enough. Have you ever thought about paperless work instrucions? Those could guide you step by step through the assembly process. If you want to, you can use Pick-to-Light, but you don't have to.

Let me be honest - I do work for the company that develops this software :) We've got a customer with a similar problem - to many customer complaints. By introducing paperless work instructions, he got them reduced by 93%.

Companies like BMW have transfered to paperless instructions in the late 90s. You could do so now.
 

Mark Meer

Trusted Information Resource
Have you ever thought about paperless work instrucions?

While the migration to electronic documents has many advantages, I'm dubious as to whether fixing assembly issues is one of them...

My experience:
We have a very complicated assembly (100s of parts, dozens of sub-assemblies..). A year ago, I was all for the transition to electronic work instructions, envisioning clutter-free workstations with only tablets networked to detailed, structured instructions, complete with lots of hi-res colour images. :tg:

Now, having such a system, I can say: sure there's value:
- easier to maintain
- instructions are better organized and easier to navigate
- waaay less paper in the assembly area

...but solving assembly issues? ...not so much.

What happens is similar to Boeing's experience. Detailed manuals/work instructions are great for training purposes, but once you've been doing the job for awhile, leafing through hundreds of pages (whether paper or electronic) each time you do the job just isn't reasonable to expect.
The tendency is for workers to think "ya, ya, I know what I'm doing. Done it hundreds of times already..." ...and hence things get overlooked.

That's why checklists are invaluable. They boil the details down to just those elements that are critical to check, and ensures that no sub-assembly (or final assembly in the case of release acceptance) goes forward in the process unless it has first met all its critical requirements/checks.
 
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R

Reg Morrison

Suggestions much appreciated. Thanks.
You have already received some very insightful suggestions.

The one I would like to share with you is: do not forget organizational culture. Assembly technicians MUST HAVE pride in the quality of the work and workmanship. Does your organizational culture emphasize quality of workmanship? If your company allows for sloppy work to be performed and shipped, I believe that you wont be able to change the situation.

In the past, I have seen organizations experiencing significant workmanship improvements when making technicians accountable to the quality of their work by somehow identifying the person responsible for the assembly and associating his/her name with the product. as an example, the AMG plant that hand builds each AMG engine for Mercedes Benz. Each one has a nameplate with the technician name on it
192459d1285275612-fun-engineer-img00447-20100622-1228.jpg

At the end of the day, you can mistake proof the process as much as you want, but people HAS to feel responsible for the quality of the work.
 

Mark Meer

Trusted Information Resource
Assembly technicians MUST HAVE pride in the quality of the work and workmanship.

:agree:
Total agreement. Good point!

On that note, it is also valuable to get the personnel input. Are they confident in the quality of their work? If not (or, commonly, just a 'meh' and a shrug), why not? ...what would they suggest to be more confident in the quality of the final product?

We've had revisions to our in-process and final-acceptance testing as a result of such interviews. :)
 
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