Customer demand in global supply networks is highly uncertain due to unexpected global and local economic conditions and, in addition, affected by seasonal demand fluctuations for final products. Therefore, in maritime transportation the... more
Customer demand in global supply networks is highly uncertain due to unexpected global and local economic conditions and, in addition, affected by seasonal demand fluctuations for final products. Therefore, in maritime transportation the design of short-sea shipping services for containerized goods has to prove its economic efficiency under varying conditions of transportation demand. Since liner shipping involves significant capital investments and huge daily operating costs, the appropriate design of the service network is crucial for the profitability of the container feeder lines. Usually, quantitative models for shipping network design are based on deterministic forecasts, which are prone to errors caused by uncertainty factors and structural changes in the development of demand. This paper puts special emphasis on the impact of seasonal demand fluctuations on the structure of the related H&S networks, the capacity of the fleet operating within the network, the deployment of ship types as well as on the associated routes of the ships. A simulation and artificial neural network based forecasting framework is developed to support the design of service networks of short-sea shipping lines. The proposed methodology has been tested for a feeder liner shipping service in the East Mediterranean and Black Sea region. Numerical results show that seasonal demand fluctuations have vital impact on the network design of container feeder lines.
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Global containership liners design their transportation service as hub-and-spoke networks to improve the access to local transportation markets and to reduce operational costs by using short-sea connections for low-volume transportation... more
Global containership liners design their transportation service as hub-and-spoke networks to improve the access to local transportation markets and to reduce operational costs by using short-sea connections for low-volume transportation lanes. These connections from the hub ports to the regional ports constitute the feeder network that is serviced by small- or medium-sized feeder containerships. In our case study investigation, we assume the feeder network design problem of a Turkish short-sea shipping company, in view of the opening of the new Candarli port near Izmir. The cost performance of three alternate feeder network configurations serving the Black Sea region is compared. For this purpose, a mixed-integer linear programming model is developed and an adaptive neighbourhood search algorithm is applied in order to determine the feeder ship fleet size and mix with routes and voyage schedules to minimize operational costs for a given planning period. Numerical results show that the new Candarli port has great potential as hub port in the Black Sea region.
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... Professor Dr. Hans-Otto Giinther Technical University of Berlin Department of Production Management Wilmersdorfer Strafie 148 10585 Berlin Germany Professor Dr ... van Marten, A., Schuur, PC 347 Models for recycling electronics... more
... Professor Dr. Hans-Otto Giinther Technical University of Berlin Department of Production Management Wilmersdorfer Strafie 148 10585 Berlin Germany Professor Dr ... van Marten, A., Schuur, PC 347 Models for recycling electronics end-of-life products Sodhi, MS, Reimer, B 377 ...
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... An extensive literature overview is then provided to point out the contribution of this paper. Section 4 presents a metaheuristic principle that is derived from Vogel's approximation method. ... Sequencing mixed-model... more
... An extensive literature overview is then provided to point out the contribution of this paper. Section 4 presents a metaheuristic principle that is derived from Vogel's approximation method. ... Sequencing mixed-model assembly lines: survey, classification and model critique. ...
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Shopfloor reality shows that many companies with complex discrete production systems have not yet found a satisfying approach to production control. Even though a large variety of theoretical approaches exists in literature, many... more
Shopfloor reality shows that many companies with complex discrete production systems have not yet found a satisfying approach to production control. Even though a large variety of theoretical approaches exists in literature, many companies do not engineer an individual production control strategy (PCS), but stick to sub-optimal standard logic provided by their Enterprise Resource Planning (ERP) software or to simple Kanban systems, what leads to suboptimal operational performance. We illustrate this challenge with a case study from industry and present an ongoing research effort to develop an engineering process to derive, parameterize, and update individual PCS. The process relies on a systems analysis perspective we propose and a simulation framework we developed. Important feedback loops known from Lean Manufacturing are considered. The vast solution space is explored starting from a simple hypothetical production system. Later, complexity drivers are stepwise reintegrated and th...
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A global supply network planning model for application in the production of chemical commodities is presented. Major modules of the model formulation reflect sales, distribution, production, and procurement activities. The objective of... more
A global supply network planning model for application in the production of chemical commodities is presented. Major modules of the model formulation reflect sales, distribution, production, and procurement activities. The objective of the model is to maximize profit by coordinating all activities within the supply chain. The model formulation is related to a real industry case.
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ABSTRACT Electric vehicles are perceived as key technology in the automotive industry to contribute to sustainable development with lower greenhouse gas emissions, less air pollution for citizens and new job opportunities with positive... more
ABSTRACT Electric vehicles are perceived as key technology in the automotive industry to contribute to sustainable development with lower greenhouse gas emissions, less air pollution for citizens and new job opportunities with positive social impact. So far the impact of electrified powertrains on the automotive industry supply chain sustainability and the development of the passenger car fleet have not been investigated in an integrated way. In our study, we focus on the long-term industry supply chain design end-to-end from the raw material exploration down to vehicle sales including the vehicle usage phase as well as reverse supply chain activities. Specifically, we address the long-term dynamics in the industry supply chain together with the fleet and powertrain development towards 2030 from a global perspective with a special focus on Germany and China. Based on industry data and using a sustainable supply chain optimization framework covering economic, environmental and social objectives, the study analyzes where jobs could be created or cut down, how total emissions in the supply chain including the usage phase of passenger cars could be reduced and how supply chain wide costs would develop. In addition, the impact of alternative market and technology scenarios as well as governmental regulations on the mix of powertrains in the vehicle fleet is investigated.
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Abstract. Inspired by a case study from industry, the production of special chemi-cal products is considered. In this industrial environment, multi-purpose equipment is operated in batch mode to carry out the diverse processing tasks.... more
Abstract. Inspired by a case study from industry, the production of special chemi-cal products is considered. In this industrial environment, multi-purpose equipment is operated in batch mode to carry out the diverse processing tasks. Often, exten-sive set-up and cleaning of the ...
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Abstract Control of logistics operations at container terminals is an extremely complex task, especially if automated guided vehicles (AGVs) are employed. In AGV dispatching, the stochastic nature of the handling systems must be taken... more
Abstract Control of logistics operations at container terminals is an extremely complex task, especially if automated guided vehicles (AGVs) are employed. In AGV dispatching, the stochastic nature of the handling systems must be taken into account. For instance, handling times of quay ...
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Page 1. OR Spectrum (2008) 30:469491 DOI 10.1007/s00291-007-0101-8 REGULAR ARTICLE A GA-based solution approach for balancing printed circuit board assembly lines Osman Kulak · Ihsan Onur Yilmaz · Hans-Otto Günther ...