Integration of scheduling and advanced process control in semiconductor manufacturing: review and outlook Scheduling optimization in semiconductor manufacturing is always a crucial task in production performance indicators such as machine utilization, cycle time and delivery times. With the increasing complexity of fabrication techniques and scales, scheduling and control activities are inevitably confronted with each other and shall be integrated correspondingly. In particular scheduling and control are mutually dependent as control requires decisions from schedules, and scheduling should take control information into account. Based on a literature survey, we propose a general review and an outlook of the expected improvements related to binding scheduling decisions and informationconstraints coming from Advanced Process Control systems in semiconductor manufacturing. Potential issues and tasks concerning this integration are addressed in this paper in order to stimulate more work in research and industrial practices.

An Optimal Control Approach to Scheduling and Production in a Process using Decaying Catalysts Abstract   This article presents a novel approach to optimise scheduling and production planning to meet seasonal demand in an industrial process using decaying catalysts, based on its formulation as a multistage mixedinteger optimal control problem (MSMIOCP). Unlike existing methodologies, the MSMIOCP formulation allows to solve this problem as a standard nonlinear optimisation problem without combinatorial optimisation methods, which can be advantageous in providing reliable, robust and efficient solutions. Using this formulation, four case studies of this problem, differing in reaction or deactivation kinetics, are investigated. Two different solution implementations are used, each having their own relative advantages. The first implementation demonstrates a bangbang behaviour for the linear scheduling controls, consistent with a theoretical analysis, but faces integration problems and does not always produce high quality solutions. The second implementation, while not demonstrating the bangbang property, always produces high quality solutions and shows the advantages of the MSMIOCP formulation over existing methodologies.