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Item type:Publication, Access status: without files , Logistic operating curves for closed queueing systems: Enhancing container terminal productivity through shared queuesContainer terminals are vital nodes in global supply chains, linking maritime and land transport. Terminal operators face the critical challenge of balancing vessel handling times and operational costs – a conflict of objectives. Building on our previous work that introduced an engineering-oriented approach using Logistic Operating Curves and an extended Kingman approximation for ship-to-shore crane productivity under fixed vehicle allocations, this paper advances the model to accommodate shared vehicle queues. In such configurations, terminal trucks serve multiple ship-to-shore cranes from a common pool, preserving the closed queueing system characteristics inherent to terminal operations.Publicationtype: Conference Paper32 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , PPS-Report 2025 Wirtschaftsstandort Deutschland: Studienergebnisse(Technische Universtiät Hamburg, 2026-09); ; ; ; Der PPS-Report 2025 liefert eine umfassende Analyse der aktuellen Lage produzierender Unternehmen am Standort Deutschland. Die Ergebnisse verdeutlichen, dass die logistische Leistungsfähigkeit – insbesondere kurze Durchlaufzeiten und hohe Termintreue – für fast alle Teilnehmer ein kritischer Wettbewerbsfaktor ist. Im Bereich Energie und Nachhaltigkeit zeigt sich eine deutliche Belastung: Steigende Energiekosten werden von der Mehrheit der Unternehmen als Problem wahrgenommen. Viele Unternehmen ergreifen bereits Maßnahmen, um gegenzusteuern. Auch die Anforderungen an die ökologische Nachhaltigkeit rücken zunehmend in den operativen Fokus. Das Themenfeld Digitalisierung und Konnektivität offenbart Licht und Schatten. Während digitale Assistenzsysteme und intelligente Agenten hohes Potential für die Zukunft versprechen, bilden heterogene Datenmodelle und fehlende Schnittstellen weiterhin signifikante Hürden bei der Umsetzung digitaler Zwillinge und der Automatisierung von Planungsaufgaben. Im Innovations- und Portfoliomanagement kämpfen Unternehmen mit einer steigenden Variantenvielfalt, die zu höheren Rüstaufwänden und Lagerbeständen führt. Hier wird deutlich, dass eine enge Verzahnung zwischen Produktentwicklung und PPS essenziell ist, um die Komplexität am Standort Deutschland beherrschbar zu halten.Publicationtype: Report54 37 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Assignment of orders in horizontal transport at sea-port container terminals(Springer Nature Switzerland, 2026-07-09); ; ; ; Quay cranes (QCs) represent the primary operational bottleneck at seaport container terminals due to their high capital intensity and role as critical nodes in global supply chains. Their productivity is strictly dependent on the efficient coordination of horizontal transport, specifically the assignment of transport orders to terminal trucks (TTs). While many terminals still rely on fixed TT-to-QC assignments, this approach often lacks the flexibility to handle disruptions and fluctuating workloads. This paper investigates the potential of a flexible, multi-criteria assignment procedure – considering work-in-process, travel distances, and QC waiting times – compared to traditional fixed assignments. The performance is evaluated using Logistic Operating Curves (LOCs), which map QC productivity against the number of deployed TTs. The results demonstrate that flexible assignment significantly outperforms fixed assignment in underload scenarios (low TT availability or high travel speeds), showing productivity gains of up to 17.85% during vehicle disruptions. However, this advantage diminishes as transport capacity increases. In high-utilization overload zones, the flexible method falls slightly below fixed assignment performance. This discrepancy is attributed to the timing of order assignment; making decisions when a previous task is completed, rather than at the last possible second, limits the system’s ability to react to real-time fluctuations. The study concludes that flexible assignment increases robustness during transport shortages, but achieving theoretical productivity benchmarks requires shifting toward late-assignment strategies.Publicationtype: Conference Paper74 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Modelling of logistics objectives at the sea side of container terminalsIn the context of the expanding global economy, the significance of transport chains has been increasingly recognized, with container terminals assuming a pivotal role within these networks. The competitive environment has led to pressure on these terminals, giving rise to a conflict of logistical objectives such as short vessel handling times and minimized handling costs. Previous attempts to address this issue, including simulation studies and deterministic mathematical models, have yet to be effectively implemented in practical settings due to their sensitivity to parameters and inherent complexity. This study proposes a novel engineering-centred approach utilizing Logistic Operating Curves to model terminal objectives, with a particular emphasis on quayside operations such as container handling by ship-to-shore cranes and terminal trucks. The paper explores the derivation of ideal and real Logistic Operating Curves for ship-to-shore cranes. Therefore, the well-known Kingman equation is extended to map the special characteristics of a closed queueing system. The simulation experiments conducted demonstrate that the proposed model provides sufficient accuracy in predicting mean productivities. The study concludes that the Logistic Operating Curves framework serves as an effective, understandable and adaptable method for improving terminal operations and highlights areas for further research.Publicationtype: Conference Paper122 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Simulation-based analysis of conflicting objectives of quay cranes and terminal trucks at container terminals(Technische Universität Dresden, Fakultät Maschinenwesen, Institut für Technische Logistik und Arbeitssysteme, Professur für Technische Logistik, 2025); ; ; ; Quay cranes are essential operating systems at container terminals. Their scheduling involves conflicting objectives, such as minimising vessel handling times, maximising productivity, and reducing the number of required terminal trucks. Logistic Operating Curves, known from production logistics, offer a suitable method for analysing such trade-offs and can be derived and validated through simulation. This paper proposes a simulation model of a container terminal to develop and parameterise characteristic Logistic Operating Curves. The analysis focuses on the conflict between quay cranes productivity and number of terminal trucks. Different assignment procedures for terminal truck are considered to examine their impact on system productivity.Publicationtype: Conference Paper64 20