Is provable or has it been proven either theoretically or empirically that goods that are manufactured during the middle of a work week are made with a high degree of quality than goods that are made during any other point during a work week?

Thank you for your time and consideration.

I think that this theory arose early in the 20th century when a lot of production was still done primarily by hand with skilled laborers and artisans building and assembling components. Under those conditions, it was certainly conceivable that human factors could influence the quality of the product just like it seems to influence non-manufacturing jobs. The trouble with trying to quantify it now is that almost all forms of manufacturing and quality control have become so highly automated, that the worker's attitude and performance really doesn't effect the output very much. I'm not sure how you would go about setting up an experiment to measure quality of product on a daily basis of an automated production line.

Another aspect is that quality control measures have changed greatly in the last 50 years. In older times, many companies were happy as long as the product worked whenit went out the door. there wasn't much checking on the products.

Today, most companies will randomly select products off the line for testing. A defective product can lead to some expensice consiquences for a company.

I know that this idea of monday and friday cars were best avoided was common in the 50s - early 70s. However, it has gone away for the most part with modern automation.

That being said, company labor disputes can lead to quality problems. See Firestone.