|Developer Diary · You Heard It Here First · 29 January 2005|
|The History of TQM|
This weekend I will be writing an article about software quality technique. Relevant to that will be a mention of TQM, a modern, hyper-managerial concept. I think of TQM in a much different way than the typical corporate bureaucrat so I thought today I would write a brief history of TQM to clear up some of the confusion that exists about it.
Originally what got TQM started was TPM "Total Productive Maintenance". It was invented by Toyota, not by W. Edwards Deming or by the U.S. Navy as many people think. In fact, Deming strongly disliked the TQM term that later was attached to his teachings by other people. Confused yet? Let's start at the beginning.
After the war the United States and Great Britain occupied Japan with around half a million troops and other personnel and ran the country as a military dictatorship. One of the civilians General MacArthur summoned to Japan to help run the conquered nation was a statistician named William Edwards Deming. Deming had a number of interesting ideas about improving manufacturing processes and his combination of fussy mathematics with personal pride and workmanship meshed well with the Japanese mentality. The Japanese developed a huge respect for Deming and today he is greatly revered there.
Deming's central thesis was that even though mass-produced items are supposed to be identical, in practice they will always vary from one another. Therefore, the industrial process should include a cycle for observing these variations and changing the process in order to reduce them. He called this cycle the "Shewhart Cycle" and it came to be known as Plan-Do-Check-Act (PDCA)--the "act" part of the cycle being where the process is changed to reflect quality checks.
This kind of thinking had a permanent influence on Japan's industrial development that long outlasted the American occupation which ended in 1952. Large Japanese industrial concerns tried to use the kinds of strategic thinking Deming taught in their operations. The most important of these efforts are what took place at Toyota in the late 1960s. At that time Toyota, a truck manufacturer, decided to begin producing passenger cars and they made a determined effort to appraise and improve their methods at a fundamental level. They succeeded phenomenonally at this and by 1980 were producing the highest quality automobiles in the world. They called their new methods "Total Productive Maintenance" or TPM.
What Toyota discovered was that the dominant cause of product defects was wear in the machines that made the parts. In turn this wear was caused by the accumulation of dirt and chips (metal shavings). The problem was that workers followed the basic American practice which was to operate a machine until it broke and only then call in an engineer to fix the machine. In some cases they would just throw the machine away and order a new one from America. This resulted in defective parts as the machine wore down and lack of productivity while the machine was waiting to be fixed or replaced. Another complication was that workers tended to move from machine to machine and often confusion resulted. How could systemic problems like this be fixed?
To solve the problems Toyota completely changed the way it operated its plants. First of all, they stopped moving workers around as much and assigned workers to have responsibility over individual machines. The next step was to require workers to keep special notebooks documenting their machine. Before this was done machines were more or less black boxes to the workers. The new way required the men to document not only how the machine operated, but its entire maintenance history and how it worked internally. Workers started taking apart their machines to learn about them and document their findings. Instead of hoarding mechanical knowledge in a few absentee engineers every worker started to have this kind of expertise.
The next step was to tackle the dirt. In the 1965 Toyota's factories looked like American factories: chips and dirt everywhere. They would change that. Since dirt was responsible for the wear that was causing defects it would be eliminated. They started on the outside by creating sweeping and cleaning regimens. Then they started regularly taking apart their machines to clean them. Finally they put their expertise to work and started designing special guards and covers to keep dirt and chips out of machines permanently.
The last step in the equation was systematic preventative maintenance. Part of their documentation efforts was to carefully study any irregularity in machine operation. For example, if a machine began to vibrate in the old days they would ignore it until the machine broke, like Americans. In the new way they would immediately stop any machine that was vibrating and take apart the machine to discover the cause. Because they now actually had started to learn how the machines worked internally this was possible. The worker (NOT an engineer) would then attempt to fix the problem. In some cases these procedures led Toyota to actually redesign and modify parts inside their tooling to improve it.
The results of these efforts are well-known: not only did Toyota start making the highest quality cars in the world but by 1980 they dominated the import market. Today Toyota is the most profitable car manufacturer in the world by a large margin.
With this kind of success other Japanese and even American manufacturers became interested in their methods. Perhaps, more significantly, so did the military. The US Navy began to develop what it called "Total Quality Management" around 1980 which was based on a collection of Japanese models, the most important of which was Toyota's TPM. By the late 80s Secretary of Defense Carlucci mandated that these ideas be adopted throughout the US armed forces. Corporate America followed like a little dog and TQM became mainstream.
Unfortunately most companies just pay lip service to concepts like this. They neither really understand what it is about nor do they have the will to make fundamental changes to the way they think and operate. For this reason if you go into most manufacturing plants even in Japan you will see the same old thing: dirt and chips everywhere and employees working machines they don't understand until they break.
What does this have to do with software anyway? Tomorrow I'll discuss it.
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