Search

This paper investigates the selection of third-party logistics providers (3PLs) based on the best prices offered by them. The focus is on outbound logistics where 3PLs must have their own distribution centres for storage and picking activities. They must also have suitable trucks for distribution to different small-scale customers. The motivation for this paper is a case study from Germany in which a furniture company with hundreds of small customers in ten zones is seeking one or more 3PLs to do the distribution. A mathematical programming model was built based on integer programming where demand per order can be expressed using exponential distribution in each customer zone. The main contribution of this paper is that it finds the best 3PLs based on the different pricing methods of the various providers; this means including the location problem indirectly using the new integer programming model. The model takes into consideration three different methods of pricing based on the offers of five 3PLs. These different methods make it difficult for the decision makers to choose the best solution, especially if specific trends in demand are expected in the future for some customer zones. The results show that future increases in demand in terms of the number of orders or order size could affect the optimal solution. The best pricing method with the lowest variability in cost over time is selected. [ABSTRACT FROM AUTHOR]

Liquidity risk is the risk that an asset cannot always be sold without causing a fall in its price because of a lack of demand for this asset. Many empirical studies examining liquidity premia have focused on government bonds. In this paper, we specifically investigate the yield differentials between liquid and illiquid German covered bonds by considering the yields of traditional Pfandbrief bonds and Jumbo Pfandbrief bonds with different maturities. In terms of credit risk the spread between the yields of these two types of covered bonds should be zero. Moreover, assuming that the liquidity risk premium is a stationary variable the yields of Pfandbrief bonds and Jumbo Pfandbrief bonds (which seem to be integrated of order one) should be cointegrated. We make use of the methodology proposed in the related field of fractional integrated models to conduct our empirical analysis. Due to the 2008–2009 global financial crisis, it also seems to be appropriate to consider structural change. To the extent that the European Central Bank has started to purchase covered bonds under the crisis pressure, our empirical evidence would have a high relevance for monetary policymakers as far as the liquidity risk is concerned. Here, our results indicate fractionally cointegrated yields before and after the crisis, while the degree of integration of the spread increases strongly during the crisis. [ABSTRACT FROM AUTHOR]

We present the problem of planning mobile tours of inspectors on German motorways to enforce the payment of the toll for heavy good trucks. This is a special type of vehicle routing problem with the objective to conduct as good inspections as possible on the complete network. In addition, we developed a personalized crew rostering model, to schedule the crews of the tours. The planning of daily tours and the rostering are combined in a novel integrated approach and formulated as a complex and large scale Integer Program. The main focus of this paper extends our previous publications on how different requirements for the rostering can be modeled in detail. The second focus is on a bi-criteria analysis of the planning problem to find the balance between the control quality and the roster acceptance. Finally, computational results on real-world instances show the practicability of our method and how different input parameters influence the problem complexity. [ABSTRACT FROM AUTHOR]

The energy sector continues to undergo substantial structural changes. Currently, the expansion of renewable energy sources and the decentralisation of energy supply lead to new players entering the market who pursue different objectives and have different preferences. Thus, multiple and usually conflicting targets need to be considered. Moreover, recent public reactions towards infrastructure projects highlight the importance of considering public acceptance as a key dimension of decision making in the energy sector. As a result, decision processes grow more complex at all levels from political to strategic, tactical and operational decisions in companies. We therefore present an approach combining power systems analysis considering grid constraints and multi-criteria decision analysis. The approach focusses on multi-dimensional sensitivity analyses allowing for simultaneous variations of the different preference parameters determined within the decision analysis aimed at facilitating preference elicitation and consensus building in group decisions. The focus of the paper is the demonstration of the presented approach for a power generation and transmission planning case study in the context of the energy transition in Germany. [ABSTRACT FROM AUTHOR]