The block-based cycle time estimation algorithm for wafer fabrication factories

Abstract

Cycle time is both an important performance measure and requisite input data for performing production planning. However, the interactive effects between some factors such as process complexity and variety of workstations, leads to difficulty in estimating cycle time. To solve these problems, this study developed a block-based cycle time estimation algorithm, called BBCT, to estimate the total cycle time for each kind of wafer process. Process was divided into numerous blocks. The block cycle time is induced by batch and loading issues. The BBCT algorithm is used to derive the cycle time induced by the batch issue according to the process characteristics within each block. A queuing time model is used to derive the waiting time resulting from the loading issue. The simulation results show that the cycle time estimation performance is much improved by the BBCT algorithm. Significance: The proposed BBCT algorithm can improve the performance of cycle time estimation, and served as the basis for setting production targets.