Is there any truth to the "day-of-the-week build quality variance", or is it just an old wives' tale?

[bigoldthor]

I know this has been kicked around for years on the interwebs. I did a little bit of googling on it this weekend but found nothing definitive, certainly nothing scientific. Just curious what anyone here has read, heard, or experienced.

FWIW, my build date was on a Tuesday.

 

[piening2150]

Old wives tale. For one thing, Sterling Heights -where the DT Ram 1500 is built- runs 6 days a week (normal schedule, but they usually work Sunday too) with 3 crews so one person's "last workday of the week" is another's "weekend" and a third person's "mid work week".

Has more to do with the individual than anything. If they don't give a **** on the last day, what makes you think they give a **** any other day?

 

[Willwork4truck]

Maybe not in auto production but I can pretty much guarantee you that my Monday mornings are kinda' sucky...

 

[papac0rn]

My last F150 was horrible and I think it was built on either a Monday or Friday. My Ram was built on a Thursday morning and its been really good (knock on wood).

 

[pinkerton]

Many of the problems we have are the result of suppliers or design and not assembly. I do believe performance at the assembly plant comes in waves - the plant I used to work in would start to get high rates of repair in trim and then the plant manager would scream and yell until things improved. This happened every month or so.

 

[Willwork4truck]

Here's a 2019 article that gives their thoughts: https://autowise.com/7-automotive-myths-exploded-that-most-people-still-believe/

Myth Number Four: Don’t buy a car built on a Monday or a Friday
This one has been around forever. Back in the days of less cooperative union and management relationships, absenteeism would skyrocket on Mondays and Fridays. With a far better partnership now between the companies that sell the cars and the men and women who make them, this kind of fluctuation in absenteeism simply doesn’t occur.
The root of this misconception was that with fewer workers, the cars wouldn’t be assembled properly as they whisked down the assembly line. The companies had a very simple cure – they just turned down the speed of the line. Fewer cars were built those days but they didn’t suffer any additional quality problems.
End of copied article

While this 2014 article says that Fridays are the "least productive" days: https://www.getflow.com/blog/productive-day
I've quoted just a portion of the article: ...
"As you can see, Monday and Tuesday are the most productive days. And the least productive day of the week is - drumroll - Friday.
Surprised? Probably not.
After all, which day kicks off your weekend? Friday. Which day puts your workweek to bed? Friday. Little shock that Friday is our least productive workday…
What is shocking is by how much Friday slumps.
We calculated daily averages for all of the meaningful things people do in Flow - creating, delegating, completing, and discussing tasks - and found that, consistently, Friday is the least productive day of the week.
When compared against the mania of Mondays, the Friday Slump sees:

• 35% fewer tasks created
• 28% fewer tasks delegated from one team member to another
• 25% fewer comments posted
• 35% fewer tasks completed

Let me repeat that last point…: 35% less work gets done on Friday than on Monday."
End of quoted article

Now lower production doesn't necessarily translate into lower quality (unless they've been watching me) so who really knows?

 

[piening2150]

Here's a 2019 article that gives their thoughts: https://autowise.com/7-automotive-myths-exploded-that-most-people-still-believe/

Myth Number Four: Don’t buy a car built on a Monday or a Friday
This one has been around forever. Back in the days of less cooperative union and management relationships, absenteeism would skyrocket on Mondays and Fridays. With a far better partnership now between the companies that sell the cars and the men and women who make them, this kind of fluctuation in absenteeism simply doesn’t occur.
The root of this misconception was that with fewer workers, the cars wouldn’t be assembled properly as they whisked down the assembly line. The companies had a very simple cure – they just turned down the speed of the line. Fewer cars were built those days but they didn’t suffer any additional quality problems.
End of copied article

While this 2014 article says that Fridays are the "least productive" days: https://www.getflow.com/blog/productive-day
I've quoted just a portion of the article: ...
"As you can see, Monday and Tuesday are the most productive days. And the least productive day of the week is - drumroll - Friday.
Surprised? Probably not.
After all, which day kicks off your weekend? Friday. Which day puts your workweek to bed? Friday. Little shock that Friday is our least productive workday…
What is shocking is by how much Friday slumps.
We calculated daily averages for all of the meaningful things people do in Flow - creating, delegating, completing, and discussing tasks - and found that, consistently, Friday is the least productive day of the week.
When compared against the mania of Mondays, the Friday Slump sees:

• 35% fewer tasks created
• 28% fewer tasks delegated from one team member to another
• 25% fewer comments posted
• 35% fewer tasks completed

Let me repeat that last point…: 35% less work gets done on Friday than on Monday."
End of quoted article

Now lower production doesn't necessarily translate into lower quality (unless they've been watching me) so who really knows?

That might be valid at a plant that runs a traditional 5x8 M-F schedule, but at SHAP Friday begins C crew's week, B crew is mid-week, and A crew is off. A crew's standard week ends on Thursday, B crew's ends Saturday, and C crew's ends Tuesday.

It would be interesting to see data on volume, productivity, quality, etc and how it trends per day/week and if it varies much with each crew combination given their alternative schedule.

As Pinkerton said, there's probably a much higher chance of supplier/part design issues than actual assembly issues. They try to "idiot proof" the assembly process as much as possible, but there's always room for improvement!