Correcting a GM Assembly Line Story – Did GM Cars Really Go To “Minor Repair” or “Major Repair?”


In the past, I've referenced a story I had heard about a GM plant in 1980's where the “completed” vehicles went to one of two areas: “minor repair” or “major repair”, the implications being that the factory relied on inspection to ensure quality and that nothing was ready to ship without some sort of repair.

I referenced the story most recently in my piece “How Toyota Can Save Your Life… At The Hospital,” attributing it to the GM Hamtramack Cadillac plant.

I had someone question the story and its accuracy, that things couldn't possibly have been that bad.

Having just done a podcast with Jim Womack and thinking that I had heard the story from him while I was at MIT, I followed up and got a recounting of the story from Jim (which I'm sharing with his permission).

For one, it wasn't Hamtramack, but it was the older Cadillac Clark Street plant, in Detroit. My dad filled in some detail that the plant was technically on “Clark Avenue” but everyone called it “Clark Street.”

Jim wrote:

You got the story from me somehow — I often use it in my talks on just how far we have come since 1980. However, let's be careful with the facts. I used the story for a metaphor on many levels. Using it as a plant “case study” misses the point.

The story. When we started the MIT car project in 1980 (or was it 1981 or…), Dave Potter, then the group VP for all the staffs, suggested that maybe we ought to learn something about the auto industry. (Not a bad idea!) I ended up making many plant tours arranged by GM. One was to the old — long, long gone — Clark Avenue Cadillac plant in Detroit. (The plant Hamtramck replaced.)

What I remember — this is 27 years ago! — is:

(a) I was 31 years old and had never been in a factory except for the 4th grade tour of the Westinghouse lightbulb plant on Roosevelt Road in Little Rock, Arkansas. (It's just over the MoPac bridge as you drive west, before the juncture with Wright Avenue…or at least it was 47 years ago.

(b) That meant that I didn't know what I was supposed to see. Instead, I could just see what I was actually seeing.

(c) What I remember seeing: amazingly bad line balance — I thought everyone worked at the same pace on a line; amazing confusion in materials handling; lots of confusion in the aisles — what were all those people doing?; and… two doors at the end of the line marked “Minor repair” and “Major repair.”

(d) At the end of the line, my young industrial engineer tour guide told me the tour was over. But I wanted to see the two mysterious rooms. This caused the plant manager to show up on the floor — my first experience with managers whose standard work included damage control.

He stated that the rework areas weren't part of the tour. So I walked straight through the “Major repairs” door to see a vast room with cars parked nose to nose. An army of reworkers were looking at build manifests and going off to get parts and tools.

After looking at the “Minor repairs” room as well, I concluded that practically everything built that day was in one room or the other. I also concluded that headcount in rework must be nearly equal to headcount on the line.

(e) This was 27 years ago and I have no notes or photographs. Could it have been this bad? I certainly clearly remember the situation as described in (a) through (d), but….it sure ain't science.

(f) What I also remember: The plant manager — who figured I was probably going to cause him a lot of problems when I reported back to Dave Potter — stated that there were also two doors at GMAD plants (remember that only Cadillac was able to keep its own assembly plant in the GMAD reorganization in the 1970s).

He stated that at GMAD plants there were also two doors. One said “Minor repairs” and the other said “Ready for shipment”.

[I can't verify that that's true: maybe it was his metaphor for how the world worked?]

But, he stated, the actual condition of the cars — with regard to conformance to specification — was the same. His view of the world was that Cadillac built a higher quality product because — to use the GM ad slogan — it sweated the details while GMAD shipped junk and knew it. And reworking your way to quality cost a lot of money, which Cadillac could afford for a luxury car but Chevy couldn't. And that was just the nature of things.

That's what I remember. Is any of this story completely accurate? Or is it full of assembly defects?

I think it's pretty accurate but I think it's really accurate as a metaphor of the mass production mindset.

And what I'm absolutely sure is that this tour caused me to realize I was studying the wrong thing in my PhD research. I was looking at industrial policy in the U.S., Japan, and Germany as an explanation of why Toyota and Honda were winning. Yet the actual reason was right in front of me on the assembly line (and, as I later learned, in product development practices and in supplier management practices and in general management methods and attitudes.)

So I changed careers that day to study how people work together to create value within companies and between companies along extended value streams. I had started my real life's work. Thank you Clark Avenue!

Thanks, Jim.

What do you think? Please scroll down (or click) to post a comment. Or please share the post with your thoughts on LinkedIn – and follow me or connect with me there.

Did you like this post? Make sure you don't miss a post or podcast — Subscribe to get notified about posts via email daily or weekly.

Check out my latest book, The Mistakes That Make Us: Cultivating a Culture of Learning and Innovation:

Get New Posts Sent To You

Select list(s):
Previous articleLeadership Means Being Aware
Next articleToyota #2 on Fortune’s "Most Admired"
Mark Graban
Mark Graban is an internationally-recognized consultant, author, and professional speaker, and podcaster with experience in healthcare, manufacturing, and startups. Mark's new book is The Mistakes That Make Us: Cultivating a Culture of Learning and Innovation. He is also the author of Measures of Success: React Less, Lead Better, Improve More, the Shingo Award-winning books Lean Hospitals and Healthcare Kaizen, and the anthology Practicing Lean. Mark is also a Senior Advisor to the technology company KaiNexus.


  1. Wow! I enjoyed Jim’s story about his GM tour…but what was really special was to learn about how Jim discovered the purpose for his life’s work.

    What a great example of a defining moment that creates vision, passion, and makes a difference.


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.