Alexander Blecken

Universität Paderborn, Paderborn, North Rhine-Westphalia, Germany

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Publications (13)2.45 Total impact

  • Beate Rottkemper, Kathrin Fischer, Alexander Blecken
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    ABSTRACT: The number of disasters and humanitarian crises which trigger humanitarian operations is ever-expanding. Unforeseen incidents frequently occur in the aftermath of a disaster, when humanitarian organizations are already in action. These incidents can lead to sudden changes in demand. As fast delivery of relief items to the affected regions is crucial, the obvious reaction would be to deliver them from neighbouring regions. Yet, this may incur future shortages in those regions as well. Hence, an integrated relocation and distribution planning approach is required, considering current demand and possible future developments.For this situation, a mixed-integer programming model is developed containing two objectives: minimization of unsatisfied demand and minimization of operational costs. The model is solved by a rolling horizon solution method. To model uncertainty, demand is split into certain demand which is known, and uncertain demand which occurs with a specific probability. Periodically increasing penalty costs are introduced for the unsatisfied certain and uncertain demand. A sensitivity analysis of the penalty costs for unsatisfied uncertain demand is accomplished to study the trade-off between demand satisfaction and logistical costs. The results for an example case show that unsatisfied demand can be significantly reduced, while operational costs increase only slightly.
    Socio-Economic Planning Sciences 01/2012;
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    ABSTRACT: The number and scale of humanitarian operations has significantly increased during the past decades due to the rising number of humanitarian emergencies and natural disasters worldwide. Therefore, the development of appropriate planning methods for optimization of the respective supply chains is constantly growing in importance. A specific problem in the context of humanitarian operations is the supply of relief items to the affected areas after the occurrence of a sudden change in demand or supply, for example, due to an epidemic or to unexpected shortages, during an ongoing humanitarian action. When such overlapping disasters occur, goods must be relocated to existing depots in a way which enables rapid supply to regions with new and urgent demand. At the same time, ongoing operations have to continue, i.e., the other regions should not suffer from shortages, and possible future emergencies must be taken into account. This is a planning situation under uncertainty as it is not known in advance if and where a disruption—and hence additional demand—will occur. In this paper, an optimization model for such situations is developed based on penalty costs for non-satisfied demand. A rolling horizon approach for solving the model is presented, and it is shown that taking into account the possibility of future disruptions can help to balance inventories and to reduce total non-served demand. KeywordsHumanitarian logistics–Overlapping disasters–Inventory relocation–Transshipment planning
    Operations Research-Spektrum 07/2011; 33(3):721-749. · 1.41 Impact Factor
  • Sabine F. Schulz, Alexander Blecken
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    ABSTRACT: Purpose – The purpose of this paper is to further the understanding of opportunities involved in horizontal cooperation in disaster relief logistics. The potential and realized benefits of horizontal cooperation in disaster relief logistics, as well as related impediments are investigated. Design/methodology/approach – Case study research into three cooperative humanitarian organization initiatives. Findings – To a large extent, the same potential synergies exist in the humanitarian as in the private sector, but not all of the potential benefits have yet been realized. Humanitarian organizations focus less on cost aspects than on lead-time and quality improvements. It is apparent that smaller organizations can benefit most from a cooperative approach. Four main impediments to a cooperative approach are identified. These concern: the perception of logistics as one of the organization's own core competences, cultural differences and mutual mistrust, a lack of transparency regarding the potential and existing benefits and inadequate relief capacities. Research limitations/implications – Research on horizontal cooperation in logistics is strengthened. A service provider model is selected as the mode of horizontal cooperation and the findings are valid only for this model. Practical implications – The presented benefits may be of assistance to humanitarian organizations assessing participation in a cooperation initiative. The indicated impediments may also serve as a guide for humanitarian organizations in horizontal cooperation considerations. Originality/value – Research on horizontal cooperation in logistics is scarce in both the private sector and the humanitarian domain. It appears that no other rigorous and systematic empirical study comparing existing logistics cooperation initiatives exists as yet.
    International Journal of Physical Distribution & Logistics Management 09/2010; 40(8/9):636-656. · 1.04 Impact Factor
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    ABSTRACT: The number of world-wide emergencies and disasters which trigger humanitarian operations is ever-increasing. Although general research contributions to supply chain management in the context of humanitarian operations have risen significantly, operations research techniques have not yet comprehensively been applied in this context. A literature review categorizes existing approaches in the pre- and post-disaster phases. Filling an identified gap in current literature, a model for optimal stock relocation under uncertainty in risk-prone post-disaster scenarios is formulated. The model is solved with an optimal and a heuristic approach. It is found that overall costs can be significantly reduced compared to a benchmark model when the uncertainty of demand in post-disaster scenarios is taken into account.
    System Sciences (HICSS), 2010 43rd Hawaii International Conference on; 02/2010
  • A. Blecken, D. Bruggemann, W. Marx
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    ABSTRACT: In this paper current usability evaluation methods are systematically examined and assessed. Thereupon, suitable evaluation methods are selected and applied in the evaluation of a learning management system. Usability evaluation methods can be distinguished in analytical and empirical procedures with either summative or formative objectives. A case example in the form of a usability evaluation of a learning management system is presented. The co-active e-learning platform koaLA provides teaching and learning material and integrates Web 2.0-technologies such as wikis, weblogs and forums. A cross-sectional survey revealed that although koaLA offers collaborative features, the majority of users of all user groups does not use them. Recommendations for koaLA are derived based on the qualitative and quantitative data from the survey.
    System Sciences (HICSS), 2010 43rd Hawaii International Conference on; 02/2010
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    01/2010;
  • Alexander Blecken
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    ABSTRACT: In the past decade, logistics in the context of humanitarian operations has more and more moved into the focus of logistics practitioners and academics. While humanitarian organisations have realised that a major part of disaster relief spending can be attributed to logistics and supply chain management activities associated with humanitarian operations, researchers have found that the area of logistics in the context of humanitarian operations gives rise to a number of unique and interesting challenges. This paper is meant as an introduction to the track Humanitarian Logistics at the 8th International Heinz Nixdorf Symposium. A recent natural disaster helps to elaborate the domain humanitarian operations. A number of important definitions are presented. Moreover, some of the specific characteristics and challenges of logistics in the context of humanitarian operations are described.
    Advanced Manufacturing and Sustainable Logistics, 8th International Heinz Nixdorf Symposium, IHNS 2010, Paderborn, Germany, April 21-22, 2010. Proceedings; 01/2010
  • Advanced Manufacturing and Sustainable Logistics, 8th International Heinz Nixdorf Symposium, IHNS 2010, Paderborn, Germany, April 21-22, 2010. Proceedings; 01/2010
  • Wilhelm Dangelmaier, Alexander Blecken, Nando Rüngener
    01/2009;
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    ABSTRACT: Humanitarian operations comprise a wide variety of activities. These activities differ in temporal and spatial scope, as well as objectives, target population and with respect to the delivered goods and services. Despite a notable variety of agendas of the humanitarian actors, the requirements on the supply chain and supporting logistics activities remain similar to a large extent. This motivates the development of a suitably generic reference model for supply chain processes in the context of humanitarian operations. Reference models have been used in commercial environments for a range of purposes, such as analysis of structural, functional, and behavioural properties of supply chains. Our process reference model aims to support humanitarian organisations when designing appropriately adapted supply chain processes to support their operations, visualising their processes, measuring their performance and thus, improving communication and coordination of organisations. A top-down approach is followed in which modular process elements are developed sequentially and relevant performance measures are identified. This contribution is conceptual in nature and intends to lay the foundation for future research.
    IJSTM. 01/2009; 12:391-413.
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    Alexander F Blecken, Bernd Hellingrath
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    ABSTRACT: Humanitarian operations in response to sudden and slow-onset crises have increased considerably both in terms of size and complexity over the last decade. This requires a coordinated approach by all actors involved in disaster or humanitarian relief efforts. Since the logistics part of disaster relief spending is accountable for a major part of disaster relief spending, it is natural to look at the supply chains of humanitarian organizations when searching for potentials for cooperation during humanitarian operations. In this paper, we have reviewed Supply Chain Management software currently used or piloted in humanitarian organizations. Their main features are presented and the tools are assessed according to criteria specific to supply chain management requirements of humanitarian operations. We find that while there is one tool which has the potential of becoming a de-facto standard, there are still gaps to be filled.
    01/2008;
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    ABSTRACT: Many planning problems are influenced by stochastical environmental factors. There are several planning algorithms from various application domains which are able to handle stochastic parameters. Correct information about these stochastic parameters has impact on the quality of plans. There is a lack of sufficient research on how to obtain this information. In this paper, we introduce a Multiagent System (MAS) that is able to model stochastic parameters and to provide up-to-date information about these parameters. Due to their access to locally available informations expert agents are used, which apply the paradigm of Bayesian Thinking in order to provide high quality information to planning agents.
    Holonic and Multi-Agent Systems for Manufacturing, Third International Conference on Industrial Applications of Holonic and Multi-Agent Systems, HoloMAS 2007, Regensburg, Germany, September 3-5, 2007, Proceedings; 01/2007
  • Alexander Blecken
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    ABSTRACT: Im Laufe der nächsten Jahrzehnte wird aufgrund einer Reihe von Faktoren weltweit mit einer Zunahme von Naturkatastrophen und humanitären Krisen gerechnet. Humanitäre Organisationen werden in Reaktion auf solche Krisen aktiv und leisten humanitäre Hilfe. Ziel der humanitären Hilfe ist, das Überleben der betroffenen Menschen zu sichern und deren selbstständige Überlebensfähigkeit wiederherzustellen. Dabei kommt der Logistik bzw. dem Supply Chain Management aufgrund der komplexen Randbedingungen, unter denen diese Hilfe geleistet wird, eine Schlüsselfunktion zu. Obwohl ein großer Anteil des Budgets solcher Einsätze auf die Bereiche Beschaffung, Transport und Lagerhaltung entfällt, haben humanitäre Organisationen oft noch nicht die Bedeutung der Logistik erkannt. Alexander Blecken untersucht in seiner Dissertation die Aufgaben und Verantwortlichkeiten von humanitären Organisationen und den Akteuren in deren Supply Chains bei der Planung und Durchführung logistischer Prozesse im Rahmen der humanitären Hilfe. Er strukturiert diese Aufgaben auf einer strategischen, taktischen und operativen Ebene und berücksichtigt dabei die Unterscheidung zwischen kurzfristiger Katastrophenhilfe und mittelfristig orientierter humanitärer Hilfe. Das entwickelte Referenz-Aufgabenmodell kann von humanitären Organisationen zur Prozessmodellierung und zum Prozessdesign eingesetzt werden. The past decade has seen an ever increasing number of natural and man-made disasters. The international community addresses the resulting humanitarian crises with concerted efforts and supports the affected communities in their survival by delivering essential goods and services ranging from food aid, water and sanitation services, to providing shelter and basic health care. Although logistics and supply chain management activities account for a large part of total expenditures in such operations, these have frequently not yet been recognised as key levers to improve effectiveness and efficiency of humanitarian organisations. Alexander Blecken investigates the tasks and responsibilities of humanitarian organisations and their supply chain partners when designing, planning, and implementing supply chain processes for humanitarian operations. He systematically presents the tasks of supply chain management in the context of humanitarian operations under consideration of both short-term disaster relief and mid-term humanitarian aid. A reference task model is developed which can be used by humanitarian organisations as a tool for process modelling and design in the areas of logistics and supply chain management. A number of supply chain processes illustrate the flexible application of the reference task model.