An Efficient Algorithm for Scheduling a Flexible Job Shop with Blocking and No-Wait Constraints*. Issue 1 (July 2017)

• Record Type: Journal Article
• Authors: Aschauer, A.; Roetzer, F.; Steinboeck, A.; Kugi, A.
• Is Part Of: IFAC-PapersOnLine. Volume 50:Issue 1(2017)
• Page Start: 12490
• Page End: 12495
• Publication Date: 2017-07
• Subjects: scheduling -- timetabling -- flexible job shop -- parallel machines -- blocking -- no-wait constraints -- construction heuristic -- tabu search -- hot rolling mill -- metal processing; Automatic control -- Periodicals; 629.805
• DOI: 10.1016/j.ifacol.2017.08.2056
• Languages: English
• ISSNs: 2405-8963

Abstract

Abstract: Optimal scheduling in industrial processes is crucial to ensure highest throughput rates and low costs. This paper presents the implementation of a scheduling algorithm in a hot rolling mill, which features several reheating furnaces and which is characterized by bidirectional material flow, blocking, and no-wait constraints. The scheduling problem is solved by a decomposition into a timetabling algorithm and a sequence optimization procedure. For the timetabling task, where the sequence of products is assumed to be fixed, a new recursive algorithm to generate a non-delay feasible schedule is developed. The sequence optimization procedure searches for the optimum product sequence and makes heavy use of the timetabling algorithm. A competitive starting sequence is generated by a construction heuristic and iteratively improved by a tabu search algorithm.