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Item type:Publication, Access status: without files , Digital assistance systems for just-in-sequence packing: key enablers for productive shipyard assembly(Springer, 2026-09-18); ; ; ; Assembly personnel in one-of-a-kind shipbuilding dedicate only a small proportion of their on-site time to value-adding activities, with non-productive tasks consuming up to 78% of their working hours. Considerable effort is expended on material procurement, information retrieval, and preparation of work sites. In addition, evolving customer requirements and internal planning deviations lead to frequent design changes in the production phase, resulting in substantial rework and elevated scrap rates. This is particularly evident for pipes, fittings, and related accessories, which are integral to numerous onboard systems throughout the vessel. Coordinating their delivery through traditional sequential scheduling results in redundant handling due to time-consuming retrieval processes for pre-manufactured parts by suppliers, and complex on-site material provision by shipyard logistics. A promising approach to overcome these challenges is to schedule frequent, small-batch deliveries in line with construction progress. While synchronizing supplier production and delivery with the assembly progress has proven to be an effective solution in automotive serial production, its application in one-of-a-kind shipbuilding is severely limited by the poor availability and accessibility of up-to-date information. To bridge this gap, this paper examines the picking and packing of installation-ready units by suppliers through the systematic use of prototype digital assistance systems integrated with a consistent database. Ultimately, this approach aims to significantly enhance the productivity of shipyard assembly workers and accelerate overall ship delivery schedules.Publicationtype: Conference Paper50 6 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Sustainability in critical raw materials for energy transition: identification of sustainability indicators and categories through a systematic literature reviewThe global energy transition is driving rapidly increasing demand for critical raw materials (CRMs) used in electric mobility, renewable energy generation, and other low-carbon production systems. While these materials are essential for decarbonization, their extraction and supply chains are associated with significant environmental and social impacts and are characterized by high geopolitical and supply risks. At the same time, sustainability-related evidence for CRM supply chains remains fragmented across studies, indicators, and assessment approaches, limiting comparability and integration into manufacturing-oriented decision support. This paper addresses this gap by identifying and structuring sustainability indicators for CRM supply chains. A systematic literature review of peer-reviewed studies is conducted following a PRISMA-based selection process. Based on this analysis, the study derives a harmonized set of core environmental and social indicators and examines how their relevance varies across materials, with a particular focus on lithium, cobalt, and neodymium. The results show that environmental indicators are more mature and consistently operationalized than social indicators, while material-specific differences remain important, particularly for lithium, cobalt, and neodymium. Building on these findings, the paper proposes a two-layer indicator framework consisting of a general baseline enabling cross-material comparability and a material-specific layer capturing dominant sustainability hotspots. The framework provides a structured and reusable basis for data extraction, model development, life cycle assessment, supply risk analysis, and decision-support for sustainable manufacturing and CRM supply chains.Publicationtype: Conference Paper41 - Some of the metrics are blocked by yourconsent settings
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 Paper31 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Evaluating the robustness of production planning and control proceduresProduction Planning and Control (PPC) procedures are very important for a stable production performance but are traditionally evaluated under the assumption of good input data quality. This reliance creates a vulnerability, as industrial environments frequently suffer from high uncertainties and systematic parameter biases that cause continuous, cumulative deviations from logistical target achievement. To address this research gap, this paper introduces a three-step evaluation framework to assess the structural robustness of PPC procedures. The proposed framework combines qualitative analysis, empirical stress testing via discrete event simulation, and mathematically sound analytical modelling using the throughput diagram. The methodology is successfully applied to evaluate the Planned Output Control (POC) procedure. The results show mathematically and empirically that closed-loop control architectures possess a fundamental advantage over open-loop systems in autonomously mitigating parameter drift. This framework enables researchers and practitioners to systematically benchmark and design robust PPC procedures prior to industrial implementation.Publicationtype: Conference Paper32 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Analysing sequencing in make-to-order companiesSufficient order sequencing configuration and implementation are key to achieving high schedule reliability and, consequently, customer satisfaction in make-to-order companies. This paper proposes a multi-method analysis approach to evaluate sequencing in make-to-order production. The approach consists of two phases: (1) data collection, including interviews, an order-level feedback data analysis, the value stream analysis for make-to-order companies, and process observations, and (2) an interpretative analysis to identify configuration and implementation deficits. As part of the feedback data analysis, a rank-based correlation analysis is introduced and validated using simulation data, providing visually accessible insights into sequencing implementation through characteristic correlation patterns. The multi-method analysis is validated in a case study, demonstrating its practical applicability and the benefits of integrating multiple analytical methods.Publicationtype: Conference Paper30 - 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 Paper118 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Concept of manufacturing control for a workstation with sequence-dependent setup times in a make-to-stock productionSequence-dependent setup times pose a challenge for a make-to-stock production. If companies apply setup-optimised sequencing to reduce setup efforts, varying replenishment times of the finished goods warehouse will increase the required safety inventories of the products. This publication presents a comprehensive manufacturing control concept for workstations with sequence-dependent setup times in make-to-stock production. The manufacturing control concept aims to effectively control the workstation and finished goods inventory, thereby enhancing the achievement of logistical objectives. The proposed concept integrates three relevant tasks of manufacturing control: order generation, capacity control, and sequencing. Cumulative Production Figures serve as a superordinate procedure, facilitating order generation and capacity control, while cyclical sequencing reduces setup efforts. Simulation experiments validate and evaluate the manufacturing control concept, demonstrating its effectiveness in managing setup efforts while limiting the negative impacts on required safety inventories. The results align with theoretical modeling and show potential for practical application in companies with make-to-stock production.Publicationtype: Conference Paper50 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A coordinated approach to apply value stream analysis to the one-of-a-kind shipbuilding supply chain(Springer, 2025-08); ; ; ; In one-of-a-kind shipbuilding, shipyards rely on highly diversified supply chains involving multiple suppliers and subcontractors. The high complexity of the processes and the unique nature of the ships present challenges for the planning and coordination of the assembly at the shipyard and for production and logistics at the suppliers. The current organization leads to long delivery times, and high inventory costs. In addition, productivity losses occur due to extra work, e.g., searching for and modifying pre-manufactured components or delayed material supply at the assembly. Synchronizing the provision of materials from suppliers with the actual assembly offers promising potential for improvement. In one-of-a-kind production, Just-in-Sequence delivery is applicable only to a limited extent due to a lack of data and insufficient communication. The systematic use of digital assistance systems in the shipbuilding supply chain offers the potential to establish a consistent database and to provide user-oriented real-time information. As a first step, this paper performs an exhaustive analysis of the shipyard and supply chain processes regarding material and information flow, and the key figures from production planning and control. For this purpose, a value stream analysis adapted to the one-of-a-kind shipbuilding process was carried out at a shipyard and three of its suppliers.Publicationtype: Conference Paper59 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , RAPID intermodal transport system: a new concept for joint transportation of passengers and freight(Springer, 2025-08); ; ; ; This paper introduces the RAPID intermodal transport system, an innovative solution that integrates passenger and freight transport using advanced Container Transfer System (CTS) technology. In response to European Commission targets for reducing road freight emissions and alleviating congestion, the RAPID system provides a sustainable, door-to-door transport alternative by enabling rapid, crane-free, vertical container transfers between truck trailers and rail wagons. This study addresses two primary research questions: (i) The feasibility of a CTS-based intermodal transport system for seamless door-to-door mobility, and (ii) its impact on transport efficiency, CO₂ emissions reduction, and economic viability in interregional transportation. To evaluate these aspects, we provide theoretical foundations for throughput analysis of such a system and develop and validate an optimization-simulation framework to match fluctuating demand under real-world conditions. A Danish case study indicates that the RAPID system can achieve a 94% reduction in freight CO₂ emissions and an 83% reduction in passenger transport emissions, improving capacity utilization and lowering operational costs. The results demonstrate that the RAPID system is a scalable, low-carbon alternative to conventional transport, capable of addressing modern logistics challenges. Future research will focus on pilot implementations, detailed economic assessments, and integration of emerging technologies to further enhance system performance and scalability.Publicationtype: Conference Paper37 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Synchronizing the shipbuilding supply chain with generic cumulative production figures(Springer, 2025-08); ; ; ; Shipbuilding is often characterized by a high complexity of the final product and a high variance of parts. Some shipyards even produce one-of-a-kind ships. Logistics performance of the shipbuilding supply chain, which is crucial for competitiveness of shipyards, is often limited due to long throughput times, high inventory levels and productivity losses, e.g., in material handling. Synchronizing supply with assembly processes in the shipyard can help to greatly reduce throughput times and inventory levels and to increase productivity, as the example of lean production in the automotive industry shows. However, neither conventional lean production concepts from high-volume production, nor existing approaches of shipyard production planning and control can support shipbuilding supply chain synchronization in a sufficient way. This paper presents a new concept for highly frequent planning and control of shipbuilding supply and production processes with a comparatively low information demand, which is based on a concept of Cumulative Production Figures (CPFs) from automotive production.Publicationtype: Conference Paper24