Mixed-integer Optimization Formulations for Site-wide Turnaround Planning

Planned chemical plant turnarounds are essential activities that ensure continuing reliability and productivity. However, turnarounds represent production disruptions for significant periods of time and, in a large chemical site network, turnarounds also affect site integration. It is of utmost importance to consider the planning and scheduling of the turnarounds to minimize these effects through appropriate manpower allocation, production, and inventory decisions. We present a mixed-integer linear programming framework for turnaround planning with long, medium and short-term considerations. We include site network structure, turnaround decisions, and several practical constraints of industrial relevance, and provide industrial case studies.