Deterministic Assembly Scheduling Problems: A Review and Classification of Concurrent-Type Scheduling Models and Solution Procedures

Many activities in industry and services require the scheduling of tasks that can be concurrently executed, the most clear example being perhaps the assembly of products carried out in manufacturing. Although numerous scientific contributions have been produced on this area over the last decades, the wide extension of the problems covered and the lack of a unified approach have lead to a situation where the state of the art in the field is unclear, which in turn hinders new research and makes translating the scientific knowledge into practice difficult. In this paper we propose a unified notation for assembly scheduling models that encompass all concurrent-type scheduling problems. Using this notation, the existing contributions are reviewed and classified into a single framework, so a comprehensive, unified picture of the field is obtained. In addition, a number of conclusions regarding the state of the art in the topic are presented, as well as some opportunities for future research.Ministerio de Ciencia e Innovación español DPI2016-80750-

MINIMIZING MAKESPAN WITH MULTIPLE ORDERS PER JOB IN A TWO MACHINE FLOWSHOP WITH ITEM PROCESSING

Abstract: New semiconductor wafer fabrication facilities use Front Opening Unified Pods (FOUPs) as a common unit of wafer transfer. Since the number of pods is limited due to high costs, and the increase in wafer size to 300-mm reduces the number of wafers required for a customer order, combining multiple orders into a single job is a necessity for efficient production. We investigate the multiple orders per job scheduling problem in the context of a 2-machine flowshop. A lower bound for the makespan performance measure is provided. An optimization model is presented that addresses both job formation and job sequencing