next batch of parts is put down. The overriding issue is that when the machine is needed, it had better work or the line will be shutdown in a short time (like 4 or 8 hours). High reliability and quick repair are essential elements of a JIT environment.
When Harley Davidson, the leading American motorcycle maker, became an independent company, its management decided that JIT manufacturing was the best solution to the quality problems they were experiencing at the time. The thought was with minimal part runs a quality fix would get onto motorcycles within days. They used to run months of parts at a time to optimize and amortize the set-up time. Under the old plan, it might be months before the parts and subassemblies in stock were used up and the improved part appeared in bikes.
Motorcycles were assembled in York, PA, and the engines and transmissions were made and assembled in Milwaukee, WI. The truck of engine and transmission assemblies was supposed to arrive when the York plant got down to a shift of stock. In other words, if the truck delivering the engines was more than 8 hours late, the York assembly line would have to shut down.
Now imagine running JIT with equipment that was only 70% reliable. Three times out of 10 the equipment would be down when you needed it to produce parts.
“Total productive maintenance (TPM) is indispensable to sustain just-in-time operations,” says Dr. Tokutaro Suzuki, Senior Executive Vice President of the Japan Institute of Plant Maintenance in TPM in Process Industries. In a JIT system, he emphasizes, “You have to have trouble-free equipment.” Prior to the adoption of TPM, Japanese manufacturers found it necessary to carry extra work in progress (WIP) inventory “so that the entire line didn’t have to stop whenever equipment trouble occurred. The concept is that the operator must protect his own equipment,” he explains. “Thus the operator must acquire maintenance skills.”
However, maintenance experts may still make periodic inspections and handle major repairs. Design engineers also play a big role. They must take maintenance requirements — and the cost of equipment failure — into consideration when they design the equipment, stresses Dr. Suzuki.
Another Japanese Vocabulary Lesson
Using the Japanese language, TPM focuses the energy of the organization on the actual piece of work (gemba), the actual part (genbutsu) being made, and the actual activity performed or as the Japanese translation says phenomenon (gensho).
TPM directly attacks the sources of ineffectiveness by concentrating on all the sources of loss of production (not only on the maintenance-related losses). This is important because most mistaken impressions think the focus of TPM is on maintenance whereas the true focus is on high quality output.
Where Does Efficiency Fit In?
Most companies spend enormous amounts of money on improvements in efficiency. Efficiency is defined as doing things the right way. Industrial engineers spend a great deal of effort on insuring wasted movements are eliminated from the production process. TPM can be said to take the next step. TPM looks at doing the right things right. By attacking all of the losses, TPM insures that at the end of the day, the pile of saleable parts made by the process is bigger. In some cases, after TPM, the pile of good parts is a great deal bigger.
Where did the idea for TPM come from in your plant? As mentioned, if the maintenance department initiated the program, look out. It is difficult to convince anyone that the program is not just a way to off-load maintenance work onto operations. Related to this question is another: Who is driving the effort?
What difference does your situation make to the success of TPM? If your machines are large or hazardous, or they require enormous skill to even consider fixing, then traditional approaches to TPM will not easily work. The fundamental shift is not maintenance activity to operations (which everyone seems to focus upon) but the responsibility for all production losses shifts to operations.
How disciplined is your production effort?
Although not every company needs full TPM implementation, every company has something to learn from it.
* Manufacturer of auto parts and part of the Toyota group of companies. Was established December 16, 1949 as Nippondenso Co., and subsequently renamed DENSO. As of March 31, 2005, DENSO Corporation consisted of 171 subsidiaries (64 in Japan, 33 in the Americas, 31 in Europe, and 43 in Asia/Oceania) with a total of 104,183 employees. In 2006, DENSO was listed at #207 on the Fortune 500 list.
Total
Before we can really talk about TPM, we have to define and dissect the words. The word total means we, as an organization, are all in. If this was referring to a sport, it would suggest we are going to play full out. One of the dictionary.com definitions says, “involving all aspects, elements, participants, resources, etc.; unqualified; all-out: total war.” We are in total war against deterioration and anything else that detracts from the output.
Another definition is “constituting or comprising the whole; entire; whole: the total expenditure. Of or pertaining to the whole of something....” This means that the whole organization has to align itself to support the TPM process, products, and activities.
The last definition is how deep do we go? The answer is “complete in extent or degree; absolute; unqualified.” We are all in to make TPM work.
Productive
If we are productive, we “have the power of producing; generative; creative: a productive effort.” The TPM effort is producing more output with the same or fewer inputs. So we are generating something. The second definition is important for our understanding. Productive is “causing; bringing about.” This effort will bring about some important changes.
Maintenance
Finally we have the word maintenance. Maintenance activities mean activities that are designed to keep an asset in good condition and not let deteriorate in the first place. If we maintain our weight, it means that we kept our weight the same. Many people think that maintenance is a fancy word for repair or fix. Nothing could be further from the truth — maintenance is activity that avoids the need to repair. If repair is necessary, then maintenance has not been present.
Because the scope of TPM is well beyond the concept of maintenance, we might want to call the effort something more accurate like Total Output Management. But I can leave the naming of your program up to you.
Although TPM, in its entirety, doesn’t apply in many situations, aspects do apply to all maintenance situations.
A Day in the Life of a TPM Shop
At the U.S. Mint, Jim Dunn (a composite person, not a real operator) walks into the coining shop, where he has worked for the last 11 years, to start his shift. At the beginning of every shift he takes a few minutes, starting at one end of the line of his presses, to clean, check the lubricant level and listen to each press. The routine is designed so that
