Shop floor control in the VLSI circuit manufacturing: a simulation approach and a case study

This paper introduces a new approach to design and model shop floor control techniques for wafer fabs in the very large-scale integrated circuit manufacturing industry. The new model suggests the scheduling system should be selected by considering the type of work centres–whether they are sequential or batch–and the relevance of set-up times and capacity utilisation rate. The proposed scheduling model has been tested via a simulation model of the existing system, and by using data coming from the field, which leads to consider real-life performance to be close to the output of the simulation campaign. The main results point out that the performance of batch work centres–even though they represent a reduced portion of the whole set of work centres–can remarkably affect the performance of the whole fab. In addition, relevant improvements in term of throughput rate and capital productivity can be obtained also at the shop floor level via slack-based dispatching procedures. Results are particularly appealing because they can be implemented in a very short period and without significant infrastructural investments.