Can you help improve assembly process?

[Claes Gefvenberg]

I just thought I'd mention the option to make the assembly foolproof by making it impossble to put gadgets in the wrong way. I realize that you are running small series, but it is often possible to design things assymetrically, add an extra bend to a pipe, and so on, without adding much or indeed anything to the price, but still render them impossible to put in incorrectly.

 

[John Broomfield]

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:

and like this:

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.

SimpleisGood,

You may have an assembly that is so badly designed that it can be put together wrong.

Mistake proofing starts with design of the product but continues with the design of your assembly process.

Have you engaged the assembly workers in mistake-proofing their process?

An excellent reference on this is Make No Mistake.

And YouTube has many examples of mistake-proofing.

John

 

[Wes Bucey]

I have a hunch OP does not design these assemblies, but assembles components for customers (OEMs?) who dictate design.

If this is correct, then design changes to make it impossible to mis-assemble must be negotiated with OEM.

If such negotiation is impossible, then careful attention needs to be directed at design of the layout for the assembly area so that components are assembled in the same order for every assembly with ONLY components (and the tools) for that stage of assembly present at each station and this may mean creating a transport system to move the assembly from station to station as it is assembled.

This would mean either separate assemblers or that the assembler moves with the assembly from station to station, using the tools and components at each station to proceed with assembly.

 

[John Broomfield]

Wes,

Yes, designers can escape the cost of their poor quality designs when they "throw them over the wall" to an assembly contractor.

Another lesson learned for contract review or before when developing the business relationship to reduce the cost of delivering quality assemblies.

John

 

[SimpleIsGood]

Great suggestions from everyone!

I'm ordering some mistake proof books, watching some poka yoke videos, looking at stickers the operators can sign with pride and planning to have meetings with designers and operators regarding their suggestions for making the entire process more resistant to mistakes.

Thanks.