News

In early September, Janis Neufeld was invited by Prof. Qan-Ke Pan (Shanghai University) and Prof. Xuan He (Shanghai Maritime University) to visit Shanghai. Prof. Pan is recognized as a leading scholar in the field of scheduling of production systems. During the multi-day stay, Janis Neufeld conducted a doctoral course together with our long-time research collaborator Prof. Jatinder ND Gupta (University of Huntsville, Alabama). The course focused on best practices for high-quality research in Operations Research and on strategies for successful publication.

The visit also provided valuable opportunities for exchange with doctoral students and colleagues from both Shanghai University and Shanghai Maritime University. Discussions centered on ongoing projects as well as ideas for future research collaborations. We sincerely thank our hosts for their warm hospitality and look forward to continuing and strengthening this fruitful cooperation.

Picture: Participants of the exchange and doctoral course at Shanghai University

Neue Publikation in OR Proceedings

We are pleased to announce a new high-ranking publication with the participation of Janis Neufeld as a book chapter in Operations Research Proceedings 2023! 

Beitrag:

Order acceptance and scheduling in capacitated job shops

Linß, Florian; Hewitt, Mike; Neufeld, Janis S.; Buscher, Udo; In: Operations Research Proceedings 2023 , 1st ed. 2025. - Cham : Springer Nature Switzerland ; Voigt, Guido, S. 341-347

Abstract:

We consider a capacitated job shop problem with order acceptance. This research is motivated by the management of a research and development project pipeline for a company in the agricultural industry whose success depends on regularly releasing new and innovative products. The setting requires the consideration of multiple problem characteristics not commonly considered in scheduling research. Each job has a given release and due date and requires the execution of an individual sequence of operations on different machines (job shop). There is a set of machines of fixed capacity, each of which can process multiple operations simultaneously. Given that typically only a small percentage of jobs yield a commercially viable product, the number of potential jobs to schedule is in the order of several thousands. Due to limited capacity, not all jobs can be started. Instead, the objective is to maximize the throughput. Namely, to start as many jobs as possible. We present a Mixed Integer Programming (MIP) formulation of this problem and study how resource capacity and the option to delay jobs can impact research and development throughput. We show that the MIP formulation can prove optimality even for very large instances with less restrictive capacity constraints, while instances with a tight capacity are more challenging to solve.

New publication in European Journal of Operational Research

We are pleased to announce a new high-ranking publication with the participation of Janis Neufeld in the European Journal of Operational Research! In our study entitled Minimizing Makespan and Total Tardiness for the Flowshop Group Scheduling Problem with Sequence Dependent Setup Times, we investigate the interactions between the two objectives of minimizing tardiness and makespan in a scheduling problem and part families.

Publication:

Xuan He, Quan-Ke Pan, Liang Gao, J.S. Neufeld, J.N.D. Gupta (2025) Minimising Makespan and Total Tardiness for the Flowshop Group Scheduling Problem with Sequence Dependent Setup Times, European Journal of Operational Research.

https://doi.org/10.1016/j.ejor.2025.02.00

Abstract:

The challenge of optimizing multiple objectives while considering job groups and partial due dates is prevalent in the flowshop group scheduling problem (FGSP). Despite its significance, the multi-objective FGSP with partial due dates (MFGSP) remains largely unaddressed in existing FGSP literature. In this paper, we bridge this gap by introducing a mixed integer linear programming model and an iterated greedy algorithm tailored for MFGSP with sequence-dependent group setup times, aimed at minimizing both makespan and total tardiness concurrently. Our proposed approach delves into the specific characteristics of times, acknowledging the inherent conflicts between objectives and the unique nature of each objective. We propose two novel local search operators: one inspired by the asymmetric traveling salesman problem and the other based on a domination criterion. These operators are seamlessly integrated into the iterated greedy algorithm framework, augmented with a cone-weighted scalar method as a fitness function and adaptive perturbation parameters. Extensive experimental evaluations demonstrate the efficacy and efficiency of our proposed algorithm, showcasing its capability to solve the MFGSP effectively. Through this research, we contribute a practical and versatile solution to a largely unexplored area in group scheduling optimization.

Three new publications of the chair

We are pleased about three new publications that have recently appeared with the participation of our chair!

In collaboration with Tristan Becker and Udo Buscher (both TU Dresden), the article “The distributed flow store scheduling problem with inter-factory transportation” (https://doi.org/10.1016/j.ejor.2024.10.026) was published in the renowned European Journal of Operational Research (VHB Rating A). We investigate the influence of transportation in manufacturing networks and develop efficient solution methods for machine scheduling.

The Journal of Scheduling is the most important scientific journal in the field of scheduling (also VHB Rating A) and published the paper by Julius Hoffmann (KIT Karlsruhe), Janis Neufeld and Udo Buscher (TU Dresden) entitled “Minimizing the earliness-tardiness for the customer order scheduling problem in a dedicated machine environment” (https://doi.org/10.1007/s10951-024-00814-z). It deals with the practically relevant customer order scheduling problem, in which several orders are produced for a customer and punctual completion is to be ensured.

Both publications are freely available as open access articles.

In addition, together with the project partners of the VIPES project (TU Dresden, University of Vienna, ÖBB Produktion GmbH, dwh GmbH), the article “Zielkonflikte in der Umlaufplanung für Triebfahrzeuge” was published in the journal Eisenbahntechnische Rundschau, which appeals to a broad audience in practice and science. In the article, we discuss the various objectives of rail vehicle scheduling and identify relevant trade-offs between them.

Prof. Dr. Neufeld was awarded the faculty's teaching prize at the 2024 graduation ceremony for his outstanding commitment to the Bachelor's degree courses.

The FWW Teaching Prize (1st place) was awarded for the lecture “Production, Logistics and Operations Research” after evaluating the assessments of students with regard to the summer semester 2024.

Also awarded (2nd place) was the exercise “Production, Logistics and Operations Research”, which was held by Caroline Ihloff (employee at the Chair of Management Science).

Congratulations!