In early 1992, TMM became the sole source of new Camry wagons with more than 41 seat variations exported over the world. Doug Friesen, manager of assembly for TMM, confronted seat problems resulting in drop of run ratio (production level) and in increase of overtime works, lead- time and off-line vehicle inventory.
First, reduction of seat variance is not considered as an alternative because Doug is a manager of assembly without control over sales decisions. Second, although inefficient feedback system is observed, improvement of information sharing is not considered as an alternative because Doug requires specific solutions for seat problems after all feedbacks are shared and discussed.
Analysis of Seat Problems
Two major problems are observed: process and feedback management problems in TMM and quality control management issues in KFS. Failure of seat quality management in KFS caused most seat problems such as problematic (wrong, missing, broken) parts, wrinkles, no-op of rear seat lock, and missing bolster according to the Exhibit 7 and Appendix 2. In addition, because KSF inspect 100 % of seats before shipping them, these kinds of problematic parts should not be shipped or allocated to the assembly line if the inspection process was appropriately executed. The Exhibit 8 confirmed again that most defects are caused by elements that KFS are responsible for such as metal flaw, missing part, wrong part, seat backset breakage, no-op, headrest built wrong. Regarding to TMM, most quality problems are attributed to employees in charge of tightening rear and front seat backboard and seat bolster broke in these two exhibits. Exhibit 10 and interview with Shirley, the group leader of Final 2, indicate that rear seat design or installation process has a structural problem because failure of rear seat installation is consistently observed more frequently than failure of front seat installation. In addition, this pattern is the same...