INTEGRATED LOTSIZING, SCHEDULING AND BLENDING DECISIONS IN THE SPINNING INDUSTRY

ABSTRACT In this paper, the relevance of integrated planning concerning decisions of production and blending in a spinning industry is studied. The scenario regards a plant that produces several yarn packages over a planning horizon. Each yarn type is produced using a blend of several cotton bales that must contain attributes to ensure the quality of the produced yarns. Three approaches to managing production and blending are compared; the first deals with the solution to the production scheduling and blending problems in a single integrated model. The second approach hierarchically addresses these problems. The third procedure combines features from the integrated and hierarchical approaches. These approaches are applied to a real-world problem, and their respective performances are analyzed. The third approach proved to deal with lot sizing, scheduling and blending in the spinning industry more efficiently. Moreover, the results indicate the importance of coordinating production and blending decisions.摘要 本文针对纺纱行业中生产与混棉决策的集成规划相关性展开研究。本研究场景设定为一家在计划期内生产多种纱线卷装的工厂：每一类纱线均需通过多种原棉包混配而成，原棉包需具备特定属性以保障成品纱线的质量。本文对比了三种生产与混棉管理方案：第一种将生产调度与混配问题整合至单一集成模型中求解；第二种方案采用分层方式依次解决上述两类问题；第三种方案则融合了集成式与分层式两种方案的特点。将这三种方案应用于实际工业场景问题，并对各自的性能表现进行了分析。研究结果表明，第三种方案在纺纱行业的批量规划、生产调度与混配环节中表现更优。此外，研究结果证实了协调生产与混棉决策的重要性。