Fast Schedule Recovery Method for Semiconductor Packaging Lines With Machine Failures and Constrained Time Windows

In semiconductor packaging line, a master schedule is normally created every shift to optimize production for a three-week horizon. However, semiconductor packaging lines are susceptible to machine failures, causing the master schedule to be sub-optimal or even infeasible. Specifically, machine failures can result in due dates not to be met and time window constraints to be violated. In this study, we classify machine failures in semiconductor packaging lines into two categories: short and long machine failures, which can be identified when the failure happens. To handle short machine failures, extra time is added into the processing time of each lot to make the master schedule robust. When a long machine failure occurs, a mixed integer programming model is formulated to adjust the master schedule. The master schedule is taken as a warm start, and a short period schedule is obtained using CPLEX for the semiconductor packaging line to follow immediately. In this way, the semiconductor packaging line can quickly respond to long machine failure without replacing the whole master schedule or giving the master scheduler enough time to remake a new master schedule. Thus, the negative impact of machine failure is mitigated. Using the data from shop floor, a simulation model is developed with SimPy to simulate a real-world semiconductor packaging line and evaluate the proposed method. The experiment results show that the proposed method can achieve fast response to machine failures in semiconductor packaging lines. Note to Practitioners—The semiconductor packaging line operates as a highly intricate production system. Its inherent flexibility allows for the simultaneous processing of diverse products from various orders. However, this flexibility necessitates adherence to a master schedule, often created without accounting for potential disruptions, such as machine failures. When not promptly addressed with efficient production control measures, machine failures can lead to production losses and product quality concerns. Moisture absorption and die surface oxidation are common quality issues that arise in the semiconductor packaging line, primarily caused by extended wait times in buffers. To equip production engineers with an effective solution for real production settings, this study introduces a practical tool to swiftly respond to machine failures. By implementing this tool, production teams can mitigate the impact of disruptions and ensure smoother operations in the semiconductor packaging process.