Evaluating Lateral Transshipment Policy in a Two-Echelon Inventory System

Emergency shipments from higher and/or same echelon levels are one of the popular tools to handle the stock-out position at some warehouse. Our paper deals with a lateral stock transshipment model involving one plant and two warehouses, lateral transshipment is considered as an option at each re-order decision under the standard (r,Q) inventory replenishment policy. We focus on incorporating the above stock transfer feature in the order fulfillment decision and designed an simulation to find the effect of lateral stock transfer policy on various parameters viz. average inventory at each warehouse, average number of stock-out days at each warehouse, total cost (comprising of inventory cost, stock-out cost and transportation cost). The experimental results show that the stock transfer policy has the potential to reduce the total cost, average inventory and average stock-out days. We have also compared the cases where information is shared online or with some delay. The delay is because of serial communication between the supply chain players. The results show that there are benefits of no information delay i.e. online information sharing over the case with information delay

Comparing Team Performance of the English Premier League, Serie A, and La Liga for the 2008-2009 Season

Three of the most celebrated football leagues in the world include the English Premier League (EPL), Italy’s Serie A, and Spain’s La Liga. To date, little football research has been conducted that attempts to determine why these leagues are so successful. What is it that the EPL, La Liga, and Serie A do that fosters such a high caliber of play, and what pitch factors, if any, either (1) contrast or (2) connect these prestigious leagues? The paucity of rigorous inquiry has not deterred popular speculation—common folklore has not waited for hard data. Experts rush to characterize the perceived performance characteristics of these leagues with little hesitation. And these assumptions have, to some degree, taken on a life of their own: football’s answer to urban legend. This paper searches for key similarities and differences between these leagues that are bolstered by statistically significant findings as well as evidence to identify the key pitch factors that are associated with a team’s ultimate success within its respective league

Veri zarflama analizi ile bulanık ortamda etkinlik ölçümleri ve üniversitelerde bir uygulama

Bu çalışmada; birden çok girdi kullanılarak birden çok çıktının üretildiği, girdi-çıktıların farklı ölçü birimlerine sahip olduğu ve verilerin bulanık olduğu durumlarda işletmelerin göreli etkinliğini ölçmeyi amaçlayan bulanık veri zarflama analizi (BVZA) ile etkinlik ölçüm yöntemleri incelenerek Türkiye'deki üniversitelerde uygulaması yapılmıştır. Çalışmada, 10 farklı BVZA modeli incelenerek Türkiye'deki 24 devlet üniversitesinin 2006 yılı etkinlik ölçümleri yapılmıştır. Etkinlik ölçümünde 6 adet girdi, 7 adet çıktı kullanılmış, geleneksel VZA modellerinden farklı olarak girdi ve çıktılara verilen ağırlıklarda tüm üniversiteler için ortak ağırlık kümesi kullanılmıştır. Uygulama sonunda; Sakarya, Afyon Kocatepe, Yıldız Teknik ve Çanakkale Onsekiz Mart Üniversitelerinin etkinlik değerleri % 95-100, Süleyman Demirel ve Mustafa Kemal Üniversitelerinin % 85-90, Gaziosmanpaşa, Dumlupınar, Kocaeli, Pamukkale, Muğla, Mersin ve Akdeniz Üniversitelerinin % 80-85, Kafkas ve Yüzüncü Yıl Üniversitelerinin % 70-75, Eskişehir Osmangazi ve Zonguldak Karaelmas Üniversitelerinin % 65-70, Niğde Üniversitesi'nin % 60-65, Kırıkkale ve Abant İzzet Baysal Üniversitelerinin % 55-60, Balıkesir, Adnan Menderes, Trakya Üniversitelerinin % 50-55 aralığında, Gaziantep Üniversitesi'nin % 45 çıkmıştır. Anahtar Kelimeler: Etkinlik, Bulanık, Veri Zarflama Analizi, Üniversite.\ud In this study; the efficiency measurement methods of the companies has been searched by using Fuzzy Data Envelopment Analysis (FDEA) of which purpose is the measurement of relative efficiencies of enterprises in the situations where there are more than one input that produces more than one output; where the inputs and outputs have different measurement units and where the data is fuzzy. At the same time an application of this study has been made at the universities in Turkey. In the research, 10 different FDEA models has been studied and the efficiency measurements of 24 government universities in Turkey has been made related to year 2006. While measuring the efficiency, it has been used 6 inputs and 7 outputs; and a common weight set has been used for all universities which makes this Data Envelopment Analysis different from the conventional ones. At the end of the application; Sakarya University's, Afyon Kocatepe University's, Yıldız Technical University's and Çanakkale Onsekiz Mart University's efficiency percentages have been in the interval 95% and 100%; Süleyman Demirel University's and Mustafa Kemal University's 85%-90%; Gaziosmanpaşa University's, Dumlupınar University's, Kocaeli University's, Pamukkale University's, Muğla University's, Mersin University's and Akdeniz University's 80%-85%, Kafkas University's and Yüzüncü Yıl University's 70%-75%, Eskişehir Osmangazi University's and Zonguldak Karaelmas University's 65%-70%, Niğde University's 60%-65%, Kırıkkale University's and Abant İzzet Baysal University's 55%-60%, Balıkesir University's, Adnan Menderes University's, Trakya University's percentages have been in the interval 50%-55% and Gaziantep University's efficiency percentage has been 45%. Keywords: Efficiency, Fuzzy, Data Envelopment Analysis, University

Fuzzy multicriteria analysis and its applications for decision making under uncertainty

Multicriteria decision making refers to selecting or ranking alternatives from available alternatives with respect to multiple, usually conflicting criteria involving either a single decision maker or multiple decision makers. It often takes place in an environment where the information available is uncertain, subjective and imprecise. To adequately solve this decision problem, the application of fuzzy sets theory for adequately modelling the uncertainty and imprecision in multicriteria decision making has proven to be effective. Much research has been done on the development of various fuzzy multicriteria analysis approaches for effectively solving the multicriteria decision making problem, and numerous applications have been reported in the literature. In general, existing approaches can be categorized into (a) multicriteria decision making with a single decision maker and (b) multicriteria group decision making. Existing approaches, however, are not totally satisfactory due to various shortcomings that they suffer from including (a) the inability to adequately model the uncertainty and imprecision of human decision making, (b) the failure to effectively handle the requirements of decision maker(s), (c) the tedious mathematical computation required, and (d) cognitively very demanding on the decision maker(s). This research has developed four novel approaches for effectively solving the multicriteria decision making problem under uncertainty. To effectively reduce the cognitive demand on the decision maker, a pairwise comparison based approach is developed in Chapter 4 for solving the multicriteria problem under uncertainty. To adequately meet the interest of various stakeholders in the multicriteria decision making process, a decision support system (DSS) based approach is introduced in Chapter 5. In Chapter 6, a consensus oriented approach is presented in multicriteria group decision making on which a DSS is proposed for facilitating consensus building in solving the multicriteria group decision making problem. In Chapter 7, a risk-oriented approach is developed for adequately modelling the inherent risk in multicriteria group decision making with the use of the concept of ideal solutions so that the complex and unreliable process of comparing fuzzy utilities usually required in fuzzy multicriteria analysis is avoided. Empirical studies of four real fuzzy multicriteria decision making problems are presented for illustrating the applicability of the approaches developed in solving the multicriteria decision making problem. A hospital location selection problem is discussed in Chapter 8. An international distribution centre location problem is illustrated in Chapter 9. A supplier selection problem is presented in Chapter 10. A hotel location problem is discussed in Chapter 11. These studies have shown the distinct advantages of the approaches developed respectively in this research from different perspectives in solving the multicriteria decision making problem

Modeling hydrogen fuel distribution infrastructure

Thesis (M. Eng. in Logistics)--Massachusetts Institute of Technology, Engineering Systems Division, 2004.Includes bibliographical references (p. 70-73).This thesis' fundamental research question is to evaluate the structure of the hydrogen production, distribution, and dispensing infrastructure under various scenarios and to discover if any trends become apparent after sensitivity analysis. After reviewing the literature regarding the production, distribution, and dispensing of hydrogen fuel, a hybrid product pathway and network flow model is created and solved. In the literature review, an extensive analysis is performed of the forthcoming findings of the National Academy of Engineering Board on Energy and Environmental Systems (BEES). Additional considerations from operations research literature and general supply chain theory are applied to the problem under consideration. The second section develops a general model for understanding hydrogen production, distribution, and dispensing systems based on the findings of the BEES committee. The second chapter also frames the analysis that the thesis will review using the model. In the problem formulation chapter, the details of the analytic model at examined at length and heuristics solution methods are proposed. Three heuristic methodologies are described and implemented. An in-depth discussion of the final model solution method is described. In the fourth chapter, the model uses the state of California as a test case for hydrogen consumption in order to generate preliminary results for the model The results of the MIP solutions for certain market penetration scenarios and the heuristic solutions for each scenario are shown and sensitivity analysis is performed. The final chapter summarizes the results of the model, compares the performance of heuristics, and indicates further areas for research, both in terms of developing strong lower bounds(cont.) for the heuristics, better optimization techniques, and expanded models for consideration.by Jon R. Pulido.M.Eng.in Logistic