Thesis (M.Eng.)--Chulalongkorn University, 1999

This study has been performed on the head stack assembly in the disc drive manufacturing. The study aims to improve the quality of head stack assembly (U2 product) at Seagate Technology Company by developing the process control program in the new cell. Quality tools and techniques are used to study such as FMEA, Fishbone diagram, Pareto, and statistical techniques. The closed loop feedback and fast corrective action taken has been established. The implementations is first to develop the process control plan "PCP". The following part is to set up the triggering mechanisms and corrective action flow. The third part is training to all members in the team including the operators. The fourth part is set up the cell goal and rule to let everyone in the team understood the concept and cell target. From the results of study: The final product audit (Dppm) shows significantly improvement. Defect part per million (Dppm) of U2 product was reduced from 4,100 Dppmin Q4 (April-June'98) to t 600 Dppm and 124 Dppm in September' 98 and November' 98 respectively. The key factors to achieve are, effective process control implemented, team working, management supporting, and real time corrective action taken. Standardized process control plan was initiated.