Operations Management - Toyota Manufacturing

Summary and Recommendation:

Toyota Motors Manufacturing (TMM) currently faces a huge problem due to defective seats in its Camry Model. Kentucky Framed Seat (KFS), Toyota’s sole seat supplier is responsible for majority of the problems, with missing parts and material flaws the main causes. Toyota is currently addressing these issues off-line, which is a deviation from the Toyota Production System (TPS).

Below are our recommendations to overcome the issue in the short-term and long-term:

Short-term solutions:

1. Station a Toyota Quality Control (QC) personnel at KFS to complete the quality check and/or a QC personnel at the arrival dock to check for defects before it enters the line.
2. KFS should be notified as soon as the problem is detected on the line so that a replacement can be made available at the earliest.
3. An inventory of the different seat styles can be kept as safety stock for use whenever a defective seat is encountered. Though this goes against the principles of TPS, this will provide a good short-term fix for the problem without affecting the production volumes.

Long-term solutions:

1. Educate and train KFS on the TPS system to ensure problems are detected at KFS and thorough quality checks are performed before the parts are delivered to TMM.
2. Assess the need for variety and the 36 different styles. KFS was a reliable supplier till the number of styles increased. Alternatively, TMM quality control could go to KFS to identify the source of the problem and implement tools such as the 5 Why’s to address the issues.
3. Implement the tooling change to correct the design of the hook or roll back the material change to plastic. This has to be done after a thorough root cause analysis in conjunction with Tsutsumi who are not facing the issue.
4. TMM could use an alternate supplier who can keep up with the variety requirements and minimize defects.

Since most of the problems are due to missing parts and material flaws, the line should not be stopped when a problem is detected until some of the solutions above are implemented.

If TMM is able to implement the QC check at the arrival dock, then Jidoka should be followed as assembly issues like cross-threading and wrong installation are now more likely than defective parts. Jidoka should also be implemented if there is a safety stock as mentioned above, as it makes sense to stop the line and replace the seat and this will not hold up production for too long.

JIT principles in TPS

JIT (Just-In-Time) was a guiding principle that TPS adopted to facilitate identification of waste in the production process. JIT principles that TPS incorporated were produce only what was needed, produce only how much was needed; produce only when it was needed. Creating a flowing production process was prerequisite for TPS – information flow was in line with physical flow of parts, parts were pulled from downstream instead of being pushed from upstream based on actual usage instead of scheduled usage. This required upstream stations to have the capacity of switching among parts with little setup time.