Oct 28 2017
5 years ago, I pointed out several omissions in the ASQ’s History of Quality pages, which have not been corrected. Specifically, I faulted them for ignoring the TPS/Lean approach to quality, the role of interchangeable parts technology, and the Roman philosopher Cicero, who coined the word “quality.” The first page, however, also contains what I think is an error of commission, where it credits the guilds of medieval Europe as precursors in the field, as follows:
“From the end of the 13th century to the early 19th century, craftsmen across medieval Europe were organized into unions called guilds. These guilds were responsible for developing strict rules for product and service quality. Inspection committees enforced the rules by marking flawless goods with a special mark or symbol.[…] Inspection marks and master-craftsmen marks served as proof of quality for customers throughout medieval Europe. This approach to manufacturing quality was dominant until the Industrial Revolution in the early 19th century.”
Today, that no two hand-crafted plates from Moustiers are identical is a selling point. They are perceived as works of art, not manufactured goods. In a manufactured product, the differences would be inconsistencies and therefore defects.
The purpose of medieval guilds was not to assure quality but to protect incumbents in every trade against all sorts of disruptions, from leaks of their secrets to innovations in design, manufacturing processes, or organization. Besides providing cheap labor to the masters, the interminable apprenticeships indoctrinated newcomers into the guilds and gave them a stake in perpetuating their traditions once they became masters. In the absence of patent, trademark, or copyright laws, secrecy was the only way to hold on to intellectual property and the prohibition of innovation was needed to prevent the obsolescence of the skills painstakingly learned by apprentices.
The development of interchangeable parts technology, as the first major step in quality improvement and a break from guild practices, is ignored in the ASQ pages but explicitly referenced in Shewhart’s Statistical Method From The Viewpoint of Quality Control (pp. 2-4). He even includes the following timeline:
Shewhart’s developed Control Charts 93 years ago to help manufacturers establish and sustain the capability to hold tolerances on critical product characteristics but this presupposes the existence of such characteristics and tolerances, which is a legacy of interchangeable parts technology, as explained by Shewhart.
Historian Ken Alder reports the little known 18th-century French prequel to the American story of interchangeable parts technology, and the way the gunsmiths of Saint-Étienne sabotaged its implementation in musket manufacturing, leading to the cancellation of the effort by Napoleon’s government in 1807 and a drop in the quality of French weapons.
Meanwhile, Thomas Jefferson, who had learned of this development as ambassador to France in 1785, undertook to continue it in the US, where guilds did not have the same power of obstruction and where it bore fruit decades later.