Toyota Motor Manufacturing, U.S.A., Inc.
Major Issues in the Case
Toyota Motor Manufacturing U.S.A., Inc. (TMM) has bypassed their typical response to quality issues known as "jidoka" in a special circumstance regarding seat installation. As opposed to stopping the assembly line and focusing on the underlying root of the problem, in the case of the faulty seats the cars were allowed to continue through the production line with a special marking that indicated that there was a seat defect. When the cars finished the assembly line phase they were then parked in a separate area in which the seats could be repaired or replaced. Allowing the cars to complete the assembly line saved a lot of time and expense because the team did not have to stop operations. However, at the same time it made finding the root cause of the quality issues complicated because it required more investigation and clouds the ability to clearly see what is causing the problems. Therefore, manager Doug Friesen must decide how to best go about addressing the solution to the seat problem and the production line.
Possible Solutions
There are basically three different solutions that Doug should consider. The first is to keep the current system of using the overflow lot for the quality defects. It is possible that, given more time, the crew could eventually locate the root problem under the current system and eliminate the overflow issues. The advantage to this system is that the production line does not have to be stopped for the quality issues and this maintains throughput. However, this approach deviates from Toyota's entire production philosophy and it is not addressing the root problems...
Yet since the seats are produced by a strategic partner, KFS, they have limited control over external quality issues. They can work with their suppliers closely to improve their internal quality issues, but on some level they are completely dependent on their seat suppliers.
Another option would be to return to the jidoka and andon pull stations. Although this a costly option because it stops the production line, this would put pressure on the entire station to work out the issues and improve quality standards so that such issues are resolved quickly. However, since the seats are made to order in a JIT system that mirrors the production flow on the main line, there could be significant delays in production caused by waiting for the defective seats. The production line could be down for hours while the workers waited on replacement seats from their vendor.
Another version of this option might be to also require that the jidoka and andon stations be applied to the external vendors manufacturing line. This might improve the quality issues before the seats ever get to Toyota. However, this could also interfere with the pull system and prevent the supplier from being able to keep pace with the Toyota production will. If the supplier could not produce the seats in time, then there would be the potential for the production line to be stopped in this option as well.
A final option might be to try to keep a safety stock or buffer station nearby with replacement seats. Therefore, when a quality issue was detected with a seat then a replacement could be pulled from a nearby buffer station. This would represent something of a bridge…
