Browsing by Subject "Supply Chain"
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Item Economic analysis of the meat supply chain(2009-05-15) Park, Moon-SooRecently, the meat supply chain has undergone a number of structural changes including increased concentration and a greater degree of quasi-vertical integration coordinated through contract procurement. The effects these changes have had on the meat supply chain, arranged as a complex array of producers, processors, distributors, and retailers, are not yet known. This study investigates the motives for, and consequences of, recent changes in the meat supply chain. The first essay examines causality among variables in the U.S. cattle supply chain using temporal and contemporaneous causality methodologies. Tests for structural changes reveal a likely structural change between later 1996 and early 1997 that was likely induced by the turnaround of the U.S. cattle inventory accompanied with severe droughts in Midwest. Results suggest that overall temporal causalities in the U.S. cattle supply chain become weaker after the structural change, though relatively strong causalities are found in pre-break periods. In contrast, strong contemporaneous causal relationships are founded in post-break periods. One conclusion is that recent structural changes in the industry are resulting in more rapid transmission of information through the supply chain. Causal evidence also suggests that the direction of information transmission has changed in recent times from moving generally downstream to moving generally upstream. This might be the result of increased concentration at the packer and retail levels giving rise to increased ability to ?set? prices. The second essay develops a theoretical model to investigate the dynamic effects of the contract procurement on packer competition in the spot market with general contract pricing scheme. Results indicate that packers have an incentive to consider the effects of spot market purchases on contract procurement even after accounting for hedonic characteristics of live cattle and risk aversion in cattle feeding operations. The third essay investigates the impacts of domestic and overseas animal disease outbreaks on the Korean meat supply chain. Market impacts are investigated using both forecasts and historical decomposition of price innovations based on an error correction model (ECM) of the Korean meat sector. Results indicate that while the affected markets suffered significantly from the outbreaks, the impacts seem temporary and substitute meat markets benefited significantly.Item Joint optimization of location and inventory decisions for improving supply chain cost performance(2009-05-15) Keskin, Burcu BarisThis dissertation is focused on investigating the integration of inventory and facility location decisions in different supply chain settings. Facility location and inventory decisions are interdependent due to the economies of scale that are inherent in transportation and replenishment costs. The facility location decisions have an impact on the transportation and replenishment costs which, in turn, affect the optimal inventory policy. On the other hand, the inventory policy dictates the frequency of shipments to replenish inventory which, in turn, affects the number of deliveries, and, hence, the transportation costs, between the facilities. Therefore, our main research objectives are to: ? compare the optimal facility location, determined by minimizing total transportation costs, to the one determined by the models that also consider the timing and quantity of inventory replenishments and corresponding costs, ? investigate the effect of facility location decisions on optimal inventory decisions, and ? measure the impact of integrated decision-making on overall supply chain cost performance. Placing a special emphasis on the explicit modeling of transportation costs, we develop several novel models in mixed integer linear and nonlinear optimization programming. Based on how the underlying facility location problem is modeled, these models fall into two main groups: 1) continuous facility location problems, and 2) discrete facility location problems. For the stylistic models, the focus is on the development of analytical solutions. For the more general models, the focus is on the development of efficient algorithms. Our results demonstrate ? the impact of explicit transportation costs on integrated decisions, ? the impact of different transportation cost functions on integrated decisions in the context of continuous facility location problems of interest, ? the value of integrated decision-making in different supply chain settings, and ? the performance of solution methods that jointly optimize facility location and inventory decisions.Item Management of Intellectual Property in Supply Chain Outsourcing(2012-10-19) Sen Gupta, RajorshiFirms outsource productive tasks to different locations in order to exploit factor price differentials and gain efficiencies from specialization. However, the benefits of outsourcing come with two risks. The first problem occurs when firms share their pre-existing intellectual property (IP) such as database and trade secrets with contractors. While IP is shared to facilitate the outsourcing project, the contractor may behave opportunistically and misappropriate the IP for its own benefit. Since firms derive significant value from their IP, this can lead to severe economic damages in terms of reduced market share and brand value. The second agency problem arises due to non-contractible effort exerted by the contractor. Depending on the outsourced task, shirking can lead to higher costs and poor quality product. In this dissertation, contractual solutions are developed to mitigate these agency problems associated with outsourcing. First, several IP misappropriation cases are enumerated in the context of outsourcing. The existing literature is reviewed and the limitations are addressed in the light of these actual cases. Second, theoretical models are developed by considering two forms of IP misappropriation, depending on whether a R&D contractor emerges as a direct competitor of the principal firm, or the contractor sells the principal?s IP to a competitor. Contracts are developed to implement a ?carrot and stick? strategy, whereby firms share limited IP with their contractor and also provide incentive payments to deter shirking problem. It is shown that complementary strategies like product differentiation, task modularization, and investment in technological solutions can be useful when legal enforcement is weak. It is also demonstrated that even under the possibility of IP misappropriation; firms may gain from outsourcing if in-house inefficiency is high. However, if legal enforcement is weak, outsourcing would entail higher transaction costs. Finally, an event study is conducted to examine the effect of trade secret misappropriation on the value of Lexar. While Lexar is still outsourcing, it is explored how Lexar survived the IP misappropriation problem through product differentiation and marketing strategies.Item Optimization and Simulation for Designing the Supply Chain of the Cellulosic Biofuel Industry(2012-02-14) An, HeungjoThe purpose of this dissertation is to provide an effective approach to design the supply chain (SC) of the cellulosic biofuel industry in order that it will support and accelerate the successful commercialization of the cellulosic biofuel industry. The methods of approach to this problem are (1) to assess the state-of-the-art biofuel SC studies, (2) to provide a decision support tool based on a mixed integer programming (MIP) model for the cellulosic biofuel supply chain design problem (BSCP), (3) to devise an exact solution method to solve large-scale instances of BSCP, (4) to evaluate a biomass logistics system based on biomass modules, by using new simulation elements for new machines, and (5) to compare several biomass logistics systems based on biomass module, bale, and silage, using simulation models. The first part of this dissertation broadly reviews the literature on biofuel SCs, analyzing the state-of-the-art biofuel and petroleum-based fuel SC studies as well as relating generic SC models that have been published over the last decade to the biofuel SC (An et al., 2010a). The resulting analysis proposes fertile opportunity for future research to contribute to improving biofuel SC. The second part of this dissertation formulates BSCP as a MIP model, which is a time-staged, multi-commodity flow, network design problem with an objective of maximizing profit (An et al., 2010b). The model prescribes strategic level decisions (i.e., facility locations, capacities, and technology types) as well as plans for transportation routes and material flows (i.e., quantities produced, stored, and transported) in each time period. A case study demonstrates managerial use in application to a region in Central Texas. The third part of this dissertation provides an exact solution method to solve BSCP. An embedded structure can be transformed to a generalized minimum cost flow problem, which is used as a sub-problem in a CG approach. This study proposes a dynamic programming algorithm to solve the sub-problem in O(m), generating improving path-flows. To accelerate branch-and-bound (B&B) search, it develops an inequality, called the partial objective constraint (POC), which is based on the portion of the objective function associated with binary variables. The fourth part of this dissertation evaluates a biomass module system, which is a conceptual logistics system based on large packages of chopped biomass with sufficient size and density to provide maximized legal highway loads and quick load/unload times. The last part of this dissertation evaluates economic benefits of the biomass module system, comparing it to bale and silage systems.Item The Impact of Product Contamination in a Multi-Stage Food Supply Chain(2012-07-16) Chebolu-Subramanian, VijayaFood product contamination leading to a food borne illness is real and has potentially devastating impact on supply chain operations and cost. However, it is not well understood from the quantitative perspective. This research seeks to fill this gap by providing a generic model of a multi-stage food supply chain consisting of a supplier/grower, processing center and retailer(s) and analyzing the impact of food product contamination in this model. The supplier corresponds to the farm/grower of the raw material such as fruits and vegetables, the processing center processes the raw material into a final food product and the retailer corresponds to the supermarkets and grocery stores selling the food product to a customer. A situation where a contamination occurs at the supplier or processing center potentially resulting in a food borne illness to the customer is considered. The contamination is discovered through periodic sampling tests conducted by the grower, processing center or through the outbreak of a food borne illness. The supply chain is modeled utilizing a G/G/1 queuing system at the processing center and an order- up to policy at the retailer(s). This research develops and compares multi-stage supply chain models with varying number of retailers. The negative dependence of contamination on the origin and mode of detection of the contamination is quantified. The differences in individual food product attributes which can impact the cost of contamination are analyzed. The impact of supply chain structure and properties and detection policies on the severity of potential contamination cases is studied. The most cost effective sampling strategies which companies can adopt in the event of product contamination are derived. The payoff from the implementation of a quality control process which can eradicate contamination is evaluated. A numerical study of the impact of a real-world contamination event on a tomato and lettuce supply chain is also conducted. Finally, a traceability system capable of tracking and tracing back products in the event of a food product recall is incorporated in the supply chain model. The value of traceability for different supply chain scenarios is assessed through the implementation of an ARENA based simulation model.Item Three essays concerning economic analysis associated with the supply chain(2009-06-02) Sherwell Cabello, PabloAnalyzing different aspects of the supply chain aids in understanding how firms behave, interact and respond within an industry. Some concepts used to carry out this analysis include asymmetric price transmission, event study methodology and event costing analysis. Each of these topics is discussed in this dissertation, presented as a set of three separate papers. The first paper analyzes asymmetric price transmission and elasticities of price transmission at the farm-retail level for whole and two percent milk in selected cities in the United States. The theoretical core of this paper relies on a comparison between the traditional Houck approach and the error correction model proposed by von Cramon- Taubadel and Fahlbusch. We reject the null hypothesis of symmetry for each product and city under both approaches. We also find little evidence of statistical superiority between the classic Houck approach and the error correction model. The second paper uses financial market event study methodology to calculate the economic impact on the supply chain related to one of the worst disease outbreaks in the food industry in the United States. This event began on November 3, 2003, when the Associated Press reported a hepatitis advisory in the Beaver Valley, Pennsylvania. This outbreak directly involved two publicly traded companies: Prandium and Sysco. The market model is used as the main foundation of the economic analysis. There is no evidence of abnormal rates of return or spillover effects in relation to the outbreak. However, there is evidence that volatility of returns increases after the event. The third paper develops a general conceptual economic module to quantify the impact of an animal disease outbreak. This study develops a generic economic module, which estimates cost in the face of a simulated animal disease outbreak under different mitigation strategies. This model was subsequently applied in a case study: a hypothetical case of a foot-and-mouth (FMD) outbreak in the Texas Panhandle analyzed under five different ex-post mitigation strategies. The results show that the most effective strategy is to slaughter and not to vaccinate. We conclude that analyzing the supply chain is important in understanding how markets behave.