In the early 1980s, Japanese auto makers contemplated building cars in North America. At that time, it was unclear whether cars produced outside Japan could live up to their hard-earned reputation of high quality at low cost. In 1992 Toyota meets a Serious problem, a growing number of cars were sitting off the line with defective seats or with no seats at all. Today, we will talk about this case and offer some our suggestions. We know TMM’s sole seat supplier was KFS, who operated on a sequential pull system which synchronize with TMM’s assembly line. However, the case indicates there’s quality deficiency on TMM’s production which reduced the run ratio to 85% from 95% and impacted regular delivery.
According our analyzing, we think the seats mainly account for quality deficiency. Not much long before, TMM re-designed the back seat by replacing its metal hooks with plastic ones. Given the weaker strength of plastic hooks than metal ones, it was easier to break off, causing frequent interruption on TMM’s assembly line and therefore, reducing efficiency of production as well. The reason attribute to such problem is not clear, however, through intensive meditation, the possible reasons can be confined within following aspects: Defective design of hooks on seats.
Mishandling of assembly workers.Defective quality of rough material applied by seat supplier. Deficiency on TPS.We can ascertain the exact reason by scrutinizing above aspects respectively. Defective design of hooks on seats.The defect of hook caused run ratio at TMM reduced 10%, however, at TMC, sharing same production system and design of hooks, did not encountered same problem as which happened at TMM. Therefore, the design of hook can be excluded from possible reasons. 2. Mishandling of assembly workers.
Learned from the case, there are new workers joined TMM in early April. Some of them damaged the seats by using hand tools from time to time. Which may suggest that some of those new workers could damage the seats during operation owing to not well trained or otherwise, not cautious enough following standard procedures. 3. Defective quality of rough material applied by seat supplier. KFS is the sole supplier of TMM’s seats. By sharing same design with TMC, the seats from KFS might also account for frequent quality deficiency at TMM other than mishandling of assembly workers at TMM, who might broker the hooks during operation if KFS delivered seats with defective quality. Deficiency on TPS.
TPS sharing nearly identical with TMC in Japan. As above mentioned, reducing of run ration did not happened in TMC, dose it suggests that there’s no break-off of hooks occurred in Japan. Could be positive, or could be negative and resolved through TPS. TMM standardized its response as follows. First, a team member pulled the andon cord to report the problem to the team leader before installing the defective seat. The team leader then pulled the andon cord to signal okay, and tagged the car to alert QC inspectors to the seat problem.
The car then went through the rest of the assembly line as usual with the defective seat in it. Upon line-off, the car was driven to the Code 1 clinic area to see if the problem was correctable there. If the problem called for a replacement seat, the car was moved to the overflow parking area where the replacement seat was ordered and the car waited for KFS ‘special delivery. Defective seats were returned to KFS.
This routine was made an exception to the standard practice of investigating problems on the line, even at the expense of shutting down the line, for three reasons: first, the final assembly people already knew of the problem; second, it was possible to finish building the car without seat assemblies; third, it was felt that stopping the line was too expensive given how long it took to obtain the replacement seat.
Because the TPS requirements of the operating mechanism, the workers need to immediately make group leader know it when the production line problems can not be resolved by workers and leader. And stop the production line, troubleshooting. American Toyota this mechanism, allowing the product in question to continue through the other production line processes, while avoiding stopping the production line situations affecting productivity.
However, the mechanism of the problems are obvious. So, Doug Friesen substantive issues facing is how to improve that violate the principles of JIT processes to solve unexpected problems, rather than deal with the issue of the seat. Because American Toyota’s approach is that try to ensure continuous production. This is American production and management, and it with the Toyota JIT and jidoka is contrary.