Statistical Approach for Cycle Time Estimation in Semiconductor Packaging Factories

In the semiconductor industry, to enhance customer satisfactions and ability of quick responses, the development of cycle time estimation model is very important. Cycle time estimation is an essential planning basis, which has many applications, especially on the analyses of performance indexes, capacity planning, and the assignments of due dates. In this paper, we provide a statistical approach for cycle time estimation in semiconductor plastic ball grid array (PBGA) packaging factories. Due to today's fierce competitive environments in the semiconductor industry, planners involved in PBGA packaging factories need an approach to obtain estimated cycle times with different confidence to ensure the due date assignments more accurately. Therefore, upper confidence bounds of estimated cycle times at various confidence coefficients are also presented in this paper. We demonstrate the applicability of the proposed cycle time estimation model incorporating the upper confidence bounds by presenting a real-world example taken from a PBGA packaging shop floor in a semiconductor packaging factory located in the Science-Based Industrial Park in Hsinchu, Taiwan.