Integration of Planning, Scheduling, and Control for Multi-product Chemical Systems under Preventive Maintenance

This study presents a framework to perform simultaneous planning, scheduling, and control (iPSC) under preventive maintenance (PM) for multi -product continuous manufacturing units. PM is an essential part of the chemical industry as they provide robustness to the operation and minimize potential plant shutdowns. Flexible planning periods are also investigated in this work since they can improve process economics. A case study featuring a multi-product CSTR is presented to illustrate the benefits of the proposed framework. The results show that flexible planning periods can lead to considerable economic improvement compared to fixed planning periods. Also, an appropriate PM program combined with flexible planning periods provides the opportunity to optimize the maintenance time instead of fixing those times a priori using process heuristics. Copyright (C) 2021 The Authors.