A multi-bucket time representation framework for optimal scheduling in beverage production facilities

Abstract

The lot-sizing and production scheduling problem of a real-life beverage industry is studied in this work. The plant under consideration produces numerous intermediate and final products weekly, through multiple production stages, processing units and shared resources. The production process involves unique aspects, including the potential temporary storage of intermediate products in preparation units before their utilization for the production of various final products. Moreover, overtime shifts can be employed for the timely satisfaction of pending orders. A multi-bucket immediate precedence Mixed-Integer Linear Programming (MILP) framework is developed to address the specific features of the industrial process while minimizing the operating time of the plant. Additionally, the introduction of intermediate storage vessels is examined and the mathematical model is extended to accommodate the new production layout. A comparative analysis between the two production layouts is conducted, revealing significant productivity improvements which can be achieved through simple retrofit design options.