8,552 research outputs found
On the efficiency of optimal algorithms for the joint replenishment problem: a comparative study
In this paper we proposed an efficient algorithm to solve the joint replenishment problem to optimality. We perform a computational study to compare the performance of the proposed algorithm with the best one reported in Viswanathan [6]. The study reveals that for large minor set-up costs and moderate major set-up cost, our algorithm outperforms the latter.inventory;joint replenishment;deterministic demand
A Continuous Review Inventory Model with Advance Policy Change and Obsolescence
In this paper, we consider a continuous review inventory system of a slow moving item for which the demand rate drops to a lower level at a pre-determined time. Inventory system is controlled according to one-for-one replenishment policy with fixed lead time. Adaptation to the lower demand rate is achieved by changing the control policy in advance and letting the demand take away the excess stocks. We showed that the timing of the control policy change primarily determines the tradeoff between backordering penalties and obsolescence costs. We propose an approximate solution for the optimal time to shift to the new control policy minimizing the expected total cost during the transient period. We found that the advance policy change results in significant cost savings and our model yields near optimal expected total costs.inventory control;obsolescence;spare parts;excess stock;installed base;advance policy changes
Flexibility in Port Selection: A Quantitative Approach Using Floating Stocks
Ports provide a number of logistical choices concerning storage, onward transport, and postponement. We investigatethe routing flexibility offered by ports with a central location with respect to the hinterland. This flexibilityis investigated using an illustrative case in which a number of alternative strategies are evaluated by means ofsimulation. Detailed cost data was used for the illustrative case. The combination of a simulation model anddetailed cost data allows us to quantify the value of the rerouting flexibility. A combination of using regionaldistribution centers and a European Distribution Center results in the lowest cost per container.supply chain;floating stock;intermodal transport;inventories;port selection
Generalized Solutions for the joint replenishment problem with correction factor
In this paper we give a complete analysis of the joint replenishment problem (JRP) under constant demands and continuous time. We present a solution method for the JRP when a correction is made for empty replenishments, and we test the solution procedures with real data. We show that the solutions obtained differ from the standard JRP when no correction is made in the cost function. We further show that the JRP with correction outperforms independent ordering. Additional numerical experiments are presented.inventory;joint replenishment;correction factor
Controlling inventories in a supply chain: a case study
This article studies specific aspects of the joint replenishment problem in a real supply chain setting. Particularly we analyze the effect on inventory performance of having minimum order quantities for the different products in the joint order, given a complex transportation cost structure. The policies suggested have been tested in a simulation model with real data.Inventory;Supply chain management;Minimum order quantities;Joint replienishment
New Bounds for the Joint Replenishment Problem: Tighter, but not always better
In this paper we present new bounds on the basic cycle time for optimal methods to solve the JRP. They are tighter than the ones reported in Viswanathan [7]. We carry out extensive numerical experiments to compare them and to investigate the computational complexity.computational complexity;joint replenishment problem;bounds
Review of Arjo Klamer’s Speaking of economics: how to get into the conversation
__Abstract__
Arjo Klamer wants to change the way we think about economics. He
argues that economics is not a body of accumulated knowledge, a
mirror of the economic world out there, or rhetoric (the art of
persuasion), but rather a bunch of conversations. In his recent book,
Speaking of economics (2007), he introduces the term conversation in
order to show that this perspective helps us understand the practice of
economics better
Determination of recovery effort for a probabilistic recovery system under various inventory control policies
In this study we investigate the desired level of recovery under various inventory control policies when the success of recovery is probabilistic. Recovery process is modelled as a single stage operation and recovery effort is represented by the expected time spent for it. The effect of increasing recovery effort on the success probability together with unit cost of the operation is included by assuming general forms of dependencies. The desired level of recovery is investigated under four inventory control policies for a wide range of system parameters. In this article, we present our computational results and their managerial implications.inventory control;probabilistic recovery
The Vienna circles: cultivating economic knowledge outside academia
__Abstract__
This article examines the intellectual scenery of interwar
Vienna. It argues that its central institution was not academia, but rather
the circles (‘Kreise’). The prominence of these circles can partly account
for the creative outburst in the social sciences in interwar Vienna.
The article also helps to explain the peculiar character of the knowledge
produced in interwar Vienna which is just as much concerned with
social and political issues as it is with more traditional scientific issues.
The lack of formal institutions and the marginal position of the
University of Vienna also had downsides. It caused uncertainty in terms
of career prospects and professional identities, although the informal
interaction within the circles full of rituals and alternative institutions
could partly make up for this. The uncertain future for scholars
ultimately contributed to the enormous wave of migration from Vienna,
frequently even before the political situation became an acute threat
De Hersenscanner en de economische wetenschap
__Abstract__
Neuroeconomics is een nieuw veld, waarin inzichten uit de neurologie worden gebruikt voor het verklaren van economische keuzes. Als nieuw veld past het in een bredere beweging in de sociale wetenschappen waarin wordt gezocht naar biologische fundering voor de theorieen, zoals bijvoorbeeld in de evolutionaire psychologie. De conferentie ‘Neuroeconomics: Hype or Hope’ in Rotterdam, was georganiseerd om te kijken wat dit nieuwe veld te bieden heeft. Voor die gelegenheid waren wetenschapsfilosofen, economen en enkele psychologen bij elkaar gekomen in de Remonstrantse Kerk. Er was van allerlei aanwezig stevige kritiek op de nieuwe methode, maar laten we eerst eens kijken wat die methode te bieden heeft
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