Janis Sebastian Neufeld

Technische Universität Dresden | TUD · Faculty of Business and Economics

In traditional machine scheduling, the focus is on determining the sequence of jobs on the machines. Meanwhile, the logistical question of how to organize the transport process between production stages frequently remains in the background. In this article, however, we consider lot streaming, offering the possibility to forward units to the next pr...

This paper studies the customer order scheduling problem in the context of additive manufacturing. The study discusses an integrated problem involving the nesting of parts as well as the scheduling of batches of nested parts onto unrelated parallel machines. A mixed-integer programming model is presented, based on existing formulations from the lit...

The customer order scheduling problem has received much attention recently due to its relevance to real world applications. In this study, the minimization of the total completion time of customer orders is studied in a dedicated machine environment, i.e. each order consists of one job on each machine. Two iterated greedy algorithms are presented t...

In industry, production is often organized in the form of a hybrid flow shop, and there is great interest in methods and algorithms for optimizing such production processes. While, thus far, methods have focused mostly on optimizing a single selected objective, it is increasingly important to address several objectives simultaneously in order to mo...

The reduction of carbon emissions plays a crucial role in achieving the goals of cleaner production. Thereby, the total amount of emissions depends not only on the used production technologies but on the electricity mix and the transportation of products to customers. Nevertheless, despite significant differences of these factors based on the locat...

This paper investigates the customer order scheduling problem on unrelated parallel additive manufacturing machines. The discussed problem comprises the splitting of orders into jobs, the allocation of those jobs to builds and finally the sequencing of builds on 3D printers. A mixed-integer programming model is presented that integrates practical r...

The crew scheduling problem with attendance rates is highly relevant for regional passenger rail transport in Germany. Its major characteristic is that only a certain percentage of trains have to be covered by crew members or conductors, causing a significant increase in complexity. Despite being commonly found in regional transport networks, discu...

Arising from a practical problem in European rail freight transport we present a heuristic solution approach that is based on a new generalized mixed integer problem formulation for the Locomotive Assignment Problem. A main focus is on the one hand on the (dis-)connecting processes between cars and locomotives and on the other hand on combining two...

Lot-sizing problems are of high relevance for many manufacturing companies, as they have a major impact on setup and inventory costs as well as various organizational implications. We discuss a practical capacitated lot-sizing problem, which arises in injection molding processes for plastic blanks at a large automotive manufacturer in Germany. 25 d...

The railway crew scheduling problem with attendance rates is particularly relevant for the planning of conductors in German regional passenger transport. Its aim is to find a cost-minimal set of duties. In contrast to other crew scheduling problems, only a given percentage of trains has to be covered by personnel. As a result, existing solution app...

A major goal of the concept of cellular manufacturing is to form independent cells. However, the formation of entirely independent cells is rarely found in practice, where inter-cellular transports of jobs are often accepted to a certain level. The resulting scheduling task in flowline manufacturing cells is referred to as cell scheduling problem....

Condition-based maintenance (CBM) has emerged as a proactive strategy for determining the best time for maintenance activities. In this paper, a case of a milling process with imperfect maintenance at a German automotive manufacturer is considered. Its major challenge is that only data with missing labels are available, which does not provide a suf...

Growing environmental awareness and the relevance of energy costs in many industries has led to the need of improving energy efficiency in operations management; hence, energy-aware scheduling (EAS) has grown in importance. In EAS three basic strategies can be identified. First, a large part of research activities is aimed at reducing energy consum...

The locomotive assignment (or scheduling) problem is a highly relevant problem in rail freight transport. For a preplanned train schedule, minimum-cost locomotive schedules have to be created so that each train is pulled by the required number of locomotives (locomotives are assigned to trains). Determining locomotive schedules goes hand in hand wi...

Heuristics based on dispatching rules are still widely used in practice as methods for effective scheduling systems. Despite the successful development of various novel dispatching rules for traditional job shop scheduling environments, nearly none of these has been applied to cellular manufacturingwithin the last decade. In this paper, we close th...

This paper addresses the flexible job shop scheduling problem with sequence-dependent setup times and where the objective is to minimize the makespan. We first present a mathematical model which can solve small instances to optimality, and also serves as a problem representation. After studying structural properties of the problem using a disjuncti...

Arising from a practical problem in German rail passenger transport, a prototype for a multi-period railway crew scheduling problem with attendance rates for conductors is developed and evaluated in this paper. The consideration of attendance rates is of increasing importance in regional transport networks and requires decision support. For this pu...

Due to its practical relevance, the flowshop group scheduling problem has received much attention in the academic and practice-oriented literature. As machines are grouped to cells and parts to part families, this problem is also known as cellular manufacturing scheduling. Group scheduling is characterized by sequencing tasks on two levels: on the...

In many practical cases of flowshop environments and especially in flowline manufacturing cells, some or all jobs may not require processing on all machines. Hence, this paper focuses on the flowshop scheduling problem with missing operations. A modification of the constructive NPS-set heuristic is proposed, which generates non-permutation schedule...

This paper focuses on the permutation flowshop group scheduling problem to minimise makespan, which is typically found in flowline manufacturing cells. In contrast to classical flowshop scheduling, it is characterised by a scheduling task at two levels: on the one hand, jobs within part families and on the other hand, a number of part families have...