Scholz-Reiter, Bernd
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Item-typ:Veröffentlichung, Electronic Seals and their Influence on the Dynamics of Container Logistics(2015-11-27); ; ; After events 9/11 the unpredictable changes have affected the global container flows in international affairs. In order to define and explore the trade-off between international security requirements and reasonably practicable measures for business, the analysis of one of the application of e-seal technology, promising to improve container transportation processes, have been evaluated in this doctoral research. The intent of this research is to investigate the impact of container detection intrusion technology on dynamics of container logistics processes at container terminals and on the complete network. In this study a model for container transhipment between two continents through several see ports consisting of several maritime terminals and customs gates is developed. In this scenario we compare transhipment processes for three different types of container seals. One type is when containers are equipped with conventional mechanical seals, the next one is an e-seal without decision making, and the last one is an e-seal with a possibility to make routing decisions. These three cases are compared and the difference in dynamics of the transport processes is investigated. First we apply the methods of queuing theory as a most suitable mathematical tool for the analysis of the dynamics. We show that this theory works effectively in case of small number of nodes. However it turns out that we arrive at its limitations when the number of nodes becomes large. For this reason we continue our investigations with help of simulation technique by means of MATLAB that has been applied to a generic container logistic network. Further we also have estimated the economical effectiveness of investments in new container secure devices. It is evaluated whether the electronic seals bring more security for container flows. As well we have investigated their influence on the business efficiency for private sector. The evaluation and analysis of modifications in dynamics of physical container flows have been accomplished through the global container supply network in the first part of the thesis. In the second main part of the doctoral research the cost-benefit analysis shows the possible costs and benefits through the implementation and use of secure container electronic seals in global container network. In this work we have determined the most feasible advantages of application of e-seals technology and the framework of its application. The influence of different types of e-seals on the dynamics of container logistics flows has been investigated, simulated and modelled analytically in the global network; various scenarios have been developed and considered to include the most happened situations in the practical cases. An evaluation model based on the cost-benefit analysis has been proposed and approved by different business cases for adoption of different types of e-seals in container system. The returns on investment index have been calculated to compare the investments in security electronic devices under different initial conditions.Dissertation1023 917 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Modellierungskonzept zur integrierten Planung und Simulation von Produktionsszenarien entwickelt am Beispiel der CFK-Serienfertigung(2014-02-17); ; ; The industrialization of CFRP production demands for new planning and engineering tools in order to develop more efficient production processes and higher automated production systems. This thesis presents a new concept for digital production engineering in the context of digital factory, which is focused on the integrated planning and simulation of complex production scenarios. As approach of model-driven engineering, a domain-specifc modeling language and a factory data model are developed in order to generate models of material flow simulation. Thereby, major challenges of digital CFRP production engineering are different technology readiness levels, complex routings of tools and materials as well as the consideration of rework and autoclave processes. These challenges motivated the development of an eight level modeling concept called GRAMOSA, which integrates the management of alternative production scenarios and focusses on an integrated production and logistics planning.Dissertation1108 1305 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Selbststeuernde Disposition im Umlaufmanagement von Verleihartikeln(2016-10-26); ; ; Being successful in global markets is a challenging task. Individual customer requirements induce a change from a seller-oriented towards a customer- oriented market. Further, technical advances lead to an adaption of production and logistic processes in individual companies and global networks. Therefore, the required methods are subject to manifold research projects. At this, the efforts reach from the development of new paradigms for the handling of complex and dynamic processes over the integration of modern information and communication technologies up to concepts for the implementation of production and logistic systems. Yet, the majority of methods show a good performance in academic scenarios, but lack an evaluation in practice. The presented work considers autonomous control in event logistics. At this, the application of methods from this field in a practice-oriented scenario is from central interest.Dissertation824 713 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Methoden zum selbststeuernden Routing autonomer logistischer Objekte - Entwicklung und Evaluierung des Distributed Logistics Routing Protocol (DLRP)(2012-12-19); ; ; Due to the growing dynamics and complexity of logistic systems, common concepts of planning and control are being pushed to their limits. In addition to that, structural changes in technology are driving new functionality into logistic systems. These circumstances require changes of processes, planning and control in this field. The new concept of autonomous control applies an object-oriented point of view. The core is the self-contained decision and routing of logistic objects within changing environments. The presented work gives a framework protocol, based on algorithms from data communication, as a general concept for autonomous routing adaptive to many fields. This framework protocol was named Distributed Logistics Routing Protocol (DLRP). The DLRP is adapted to transport and to production logistics where it is being compared to common algorithms (for VRP, PDP and FFP). This shows a comparable performance and a high potential of the DLRP to improve logistic processes.Dissertation456 142 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Produktionsplanung und -steuerung in mehrstufigen Batchproduktionen : Methoden der Loskomposition und -terminierung bei stufenspezifischen Auftragsfamilien(2016-01-20); ; ; This doctoral thesis introduces the problem of batching and scheduling non-permutation flow shops with m>=2 batch processing machines in sequence and stage specific incompatible job families. Batches are builded at each stage according to family-specific parameters. This creates a stage-interdependent batching and scheduling problem. The thesis includes the corresponding integer linear program as well as problem specific heuristics and a metaheuristic dealing with the planning problem. All methods are evaluated by real problem instances.Dissertation882 474 - Some of the metrics are blocked by yourconsent settings
Item-typ:Veröffentlichung, Green Logistics Oriented Framework for the Integrated Scheduling of Production and Distribution Networks - A Case of the Batch Process IndustryNowadays, most consumable goods are produced and transported in batches. Within the globalized environment, the flow of these batches is raising dramatically to satisfy the recurrent demands of the increasing population. Planning the flow of these batches from suppliers to customers, through dynamic logistics systems, has a high degree of uncertainties on supply chain related decisions. In order to respond effectively and efficiently to these uncertainties, the supply chain network has to be redesigned, considering the economic and environmental requirements. To handle these requirements sustainably, green logistics is a promising approach. However, there is a lack of green logistics models which integrate both the production and distribution decisions within the batch process industries. This research develops a green logistics oriented framework in the case of the batch process industry. The framework integrates the tactical and operational levels of planning and scheduling to generate the optimum production and distribution decisions. A two-stage stochastic programming model is formulated to design and manage batch supply chain. This is a mixed-integer linear program of the two-stage stochastic production-distribution model with economic-environmental objectives. The first stage is concerned with optimum schedules of the production and distribution of the required batches. The second stage subsequently generates the optimum delivering velocities for the optimal distribution routes which are resulted from the first stage. Carbon emissions under uncertainties are incorporated as a function of random delivery velocities at different distribution routes within the network of the supply chain. To examine the applicability of the developed framework, the model is verified and validated through four theoretical scenarios as well as two real world case studies of multi-national batch process industries. The results of the analysis provide some insights results into supply chain costs and emissions. Based on the results, savings of about 43 percent of the total related economic and environmental costs were achieved compared to the actual situation at the case study companies. Cost savings mean long-term profitability, which is essential to sustain a worldwide competitive advantage. Furthermore, the stochastic and expected value solutions are compared in several scenarios. The stochastic solutions are consistently better with respect to costs and emissions. Calculations indicate that up to 13 percent of total cost savings are achieved when a stochastic approach is used to solve the problem as opposed to an expected value approach. The proposed framework supports academic green logistics models and real world supply chain decision making in batch process industry. Building such a framework provides a practical tool which links being green and being economically successful.Dissertation996 345