Title: A heuristic method for batch scheduling in the pharmaceutical industry with sequence-dependent setup times
Authors: Patroklos Georgiadis
Addresses: Industrial Management Division, Department of Mechanical Engineering, Aristotle University of Thessaloniki, P.O. Box 461, 541 24, Thessaloniki, Greece
Abstract: The batch scheduling with sequence-dependent setup times is an operational problem of great importance for the pharmaceutical industry as it affects the shop performance and the provided service level. Exact solutions are a time consuming task with increased functional complexity, which calls for heuristic methods while dealing with the sequencing and scheduling of drug batches on a daily, weekly or monthly basis. This paper proposes a modified beam search method which employs dispatching rules for selecting the next batch in the sequence, and evaluates the schedule performance in terms of flow-times and due-date-based measures. The efficiency of the method is justified by using data from a pharmaceutical firm as a real-world test case. Extensive simulation experimentation reveals solutions for the firm which minimise the total setup times responding satisfactory to due-date objectives as well. In addition, it reveals insights for the sequencing and scheduling problem in the pharmaceutical industry.
Keywords: batch sequencing; flow shop scheduling; sequence-dependent setup times; pharmaceutical industry; drug batches; modified beam search; dispatching rules; flow times; due dates; simulation.
International Journal of Decision Sciences, Risk and Management, 2012 Vol.4 No.3/4, pp.342 - 353
Received: 25 May 2012
Accepted: 10 Jun 2012
Published online: 19 Apr 2013 *