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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Inventory models with weather derivatives and weather-conditional rebates for seasonal products. / CUHK electronic theses & dissertations collection / ProQuest dissertations and theses

January 2007 (has links)
Key words. Newsvendor Model, Inventory Model, Seasonal Product, Weather Risk, Weather Option, Weather Derivative, Weather-Conditional Rebate, CVaR, Mean-CVaR. / The first model considers the problem of hedging inventory risk for a newsvendor who sells a seasonal product. The newsvendor not only decides the order quantity, but also adopts a weather hedging strategy. A typical hedging strategy is to use an option that is constructed on a weather index before the season begins, which will compensate the buyer of the option if the actual seasonal weather index is above (or below) a given strike level. We explore the joint decision problem in mean-variance, expected utility, conditional value-at-risk (CVaR), and mean-CVaR frameworks. We analyze the impact of weather hedging on optimal order quantity. It is proven that the newsvendor may order more than in the absence of weather options. Numerical analysis on the sensitivity of the optimal order quantity, the risk premium of the option, the portfolio selection and the comparison between the weather option hedging and a particular operational hedging are presented as well. / The second model investigates the advantages of early sales of a seasonal product. To induce early sales, the newsvendor adopts a weather-conditional rebate program, which will pay rebates to the customers who buy the product in the preselling period if a specified weather condition for normal selling season is realized. For an example, a certain amount of refund will be paid to early buyer if the seasonal average temperature falls below the past-three-year seasonal average. Two conditional rebate programs with early booking and early purchasing are investigated and compared. Both of them can price differentiate within a customer among his/her post valuation on the seasonal product, and thus increase the sales. For the early purchasing program, it can further save inventory holding cost and ordering cost. The expected profit can be improved by the programs. Moreover, combined with weather derivatives, the conditional rebate program can manage the financial risk with the expected profit being still improved. / To investigate the means that firms may adopt in managing the adverse impacts of weather on their businesses, this dissertation proposes and analyzes two inventory models for seasonal products when the demand is sensitive to the weather in the season. Both models are formulated under the newsvendor context. / Gao, Fei. / "October 2007." / Adviser: Youhua Frank Chen. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 5002. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 108-119). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
272

Inventory models with downside risk measures. / CUHK electronic theses & dissertations collection

January 2007 (has links)
Finally, we study a multi-period, risk-averse inventory model. The objective is to maximize the expected pay-offs. The risk-averse behavior is modeled as to penalize the decision maker if a target-profit level is not satisfied for each financial reporting cycle. We recognize that the operational period is usually faster than the financial reporting cycle. Therefore, the financial reporting cycle can be considered as an integer times of the operational periods. We study this model under both accrual-basis accounting principle and cash-basis accounting principle. We prove that the optimal inventory policy is a state-dependent base-stock policy under the accrual-basis accounting method. We then show that the structure of an optimal policy is a complicated one for the cash-basis accounting method. / In this thesis we study three supply chain models which address downside risk from a different angle. We start with a commitment-option supply contract in a Conditional Value-at-Risk (CVaR) framework. We show that a CVaR trade-off analysis with advanced reservation can be carried out efficiently. Moreover, our study indicates how the corresponding contract decisions differ from decisions for optimizing an expected value. / Key words. Downside Risk Measure; CVaR; Risk; Loss-Averse; Dynamic Programming. / Owing to the growing globalization in economy and the advances in commerce, research in supply chain management has attracted large number of researchers in the last two decades. Yet standard treatments of supply chain models are mainly confined for the optimization of expected values with little reflection on risk considerations. Even for those that consider a risk measure in the objective function, there are quite few literatures employing downside risk measure. The downside risk measure takes into account only the part of the distribution that is below a critical value. Thus it indicates a safety-first strategy for decision maker. / The thesis is organized in five chapters. In Chapter 1, we provide the background and research motivation for considering downside risk measures in supply chain models. In Chapter 2, we study the pay-to-delay supply contracts with a Conditional Value-at-Risk (CVaR) framework. In Chapter 3, we study the loss-averse newsvendor problem. In Chapter 4, we extend the loss-averse model to a multi-period setting. We conclude the thesis in Chapter 5 with discussions for future research. / Then, we employ a loss-aversion utility function to characterize newsvendor's decision-making behavior. We find that when there is no shortage cost, the loss-averse newsvendor consistently orders less than a risk-neutral newsvendor. Further, we discover that the loss-averse newsvendor orders a constant quantity when the reference target is sufficiently large. We discuss the importance of initial inventory to achieve the target profit level. When the target is a decision variable, the newsvendor always sets the target no higher or no lower. / Ma, Lijun. / "October 2007." / Adviser: Houmin Yan. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 5003. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 140-154). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
273

Joint determination of sales lever and inventory control with uncertain demand. / CUHK electronic theses & dissertations collection / ProQuest dissertations and theses

January 2006 (has links)
Assuming that all unmet demand is fully lost, we begin our study by confining the sales lever to be price only, that is, z = p , and ignoring the cost for executing the sales lever. Given a stationary (s, S, p) policy, we find that the profit function for the lost-sales case exhibits the same structure as the one for the backlogging case. We further show that the relaxed assumption on the news-vendor type profit function can also be satisfied by a broad class of demand function. We can therefore extend the optimizing algorithm and the optimality analysis developed earlier to the lost-sales case. We further demonstrate that the results can be extended to the general sales lever decisions. / Assuming that unmet demand is fully backlogged, a newsvendor-type profit function which is defined as the resulting expected one-period profit with sales lever being optimized for every inventory level, fails to be unimodal. By assuming the newsvendor-type profit function to have a finite number of local maxima, we develop an efficient algorithm for finding the optimal ( s, S, z) policy with the long-run average profit derived by the renewal theory. We further identify the conditions under which the (s, S, z) policy is globally optimal. / Issues on the interfaces between operations management and marketing research have attracted much attention recently. The developments integrating marketing decisions into inventory management are not only of academic interest, but also of practical importance. With uncertain demand, this research studies the joint determination of inventory and sales lever decisions such as price, incentives to salesforce, and short-term promotions, or a combination of them. / We consider a single-item, periodic-review system with the objective of maximizing the long-run average profit over an infinite planning horizon. Demand in a period is a non-negative, discrete random variable with its distribution dependent on the sales lever chosen for the period. A replenishment order can be placed at the beginning of a period incurring both fixed and variable ordering costs. The sales lever is determined jointly, and its execution may incur possible cost, for example, promotion cost. For such a model, we take particular interest in a so-called (s, S, z) policy, which operates as follows: whenever the inventory level falls to or below s, an order is placed to bring it up to S; when the inventory level is above s, no order is issued; the choice of sales lever z depends on the inventory level. / We finally conduct an extensive numerical study for both the backlogging and lost-sales cases. We compare the benefits of the dynamic sales lever strategy with those of the semi-dynamic as well as the static sales lever strategy, and find that the profit gains are significant. By sensitivity analysis, we bring out the impact of cost parameters on the optimal solutions. / Wei Ying. / "December 2006." / Adviser: Youhua Frank Chen. / Source: Dissertation Abstracts International, Volume: 68-09, Section: A, page: 3961. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 125-131). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
274

Reduction of the causes of stock-outs in ERP supply chain management by prioritization of the causes : a case study at the City of Cape Town

Moleli, Moletsane Tarcisius January 2018 (has links)
Thesis (MTech (Business Information Systems))--Cape Peninsula University of Technology, 2018. / Enterprise resource planning (ERP) systems have a good reputation for automation and strength in the integration of business processes (BPs), therefore more and more organisations are adopting ERP systems. The City of Cape Town (CCT), a metropolitan municipality, is one of the organisations that have adopted an ERP system. CCT provides a wide range of services to residents and citizens in the Western Cape Province of South Africa. The ERP system at CCT manages the Supply Chain Management (SCM) processes, among others, to ensure good service delivery. ERP systems are able to provide statistical reports on stock-outs; however, the information provided is insufficient to link a specific stock-out to its causes within the SCM process at CCT. This makes it difficult to select the most appropriate solution to minimise the causes and number of stock-outs. The study aims to explore the possible reduction of the causes of stock-outs at CCT stores, therefore the study has adopted a qualitative research methodology with a case study research strategy. It uses subjectivism to understand the truth, with an inductive approach applied to five different interviewee groups, namely the ERP Support Department consultants, the Procurement Department, the Inventory and Stores Management Department, the Master Data Maintenance Department, and the reservation creators. A purposive sampling method is used because the study targets knowledge and experience on the subject from the interviewees in the investigation of the problem. The case is the SCM division at CCT, the unit of analysis is the CCT stores, and the unit of observation is the employees who work for the SCM division of CCT. All ethical procedures and policies of the Cape Peninsula University of Technology (CPUT) are adhered to. For the data collection, in depth semi-structured questions have been developed, and the data were analysed using thematic analysis. The leading causes of stock-outs were discovered by analysing the themes. The results revealed the themes, in descending order according to the causes of stock-outs, as follows: procedures, service delivery, suppliers, stock-outs, human resources, and systems. All the objectives were achieved, thereby answering the research questions.
275

Commodity trading strategies in the presence of multiple exchanges and liquidity constraints.

January 2009 (has links)
Li, Xu. / Thesis submitted in: December 2008. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 41-43). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background Study --- p.6 / Chapter 3 --- Model Formulation --- p.8 / Chapter 3.1 --- Trading Cost Function --- p.9 / Chapter 3.2 --- Notations and Optimality Equation --- p.11 / Chapter 4 --- Optimal Policy --- p.14 / Chapter 4.1 --- Preliminary Assumption and Results --- p.14 / Chapter 4.1.1 --- "Generalized (s, 5, H) Policy" --- p.14 / Chapter 4.1.2 --- Polya Distribution and Quasi-K-convex --- p.15 / Chapter 4.1.3 --- Assumptions --- p.20 / Chapter 4.2 --- Single Period Problem --- p.23 / Chapter 4.3 --- Finite-Period Problem --- p.30 / Chapter 4.4 --- The Algorithm --- p.36 / Chapter 5 --- Conclusion --- p.39 / Bibliography --- p.41
276

Forecasting of intermittent demand

Syntetos, Argyrios January 2001 (has links)
This thesis explores forecasting for intermittent demand requirements. Intermittent demand occurs at random, with some time periods showing no demand. In addition, demand, when it occurs, may not be for a single unit or a constant size. Consequently, intermittent demand creates significant problems in the supply and manufacturing environment as far as forecasting and inventory control are concerned. A certain confusion is shared amongst academics and practitioners about how intermittent demand (or indeed any other demand pattern that cannot be reasonably represented by the normal distribution) is defined. As such, we first construct a framework that aims at facilitating the conceptual categorisation of what is termed, for the purposes of this research, “non-normal” demand patterns. Croston (1972) proposed a method according to which intermittent demand estimates can be built from constituent elements, namely the demand size and inter-demand interval. The method has been claimed to provide unbiased estimates and it is regarded as the “standard” approach to dealing with intermittence. In this thesis we show that Croston’s method is biased. The bias is quantified and two new estimation procedures are developed based on Croston’s concept of considering both demand sizes and inter-demand intervals. Consequently the issue of variability of the intermittent demand estimates is explored and finally Mean Square Error (MSE) expressions are derived for all the methods discussed in the thesis. The issue of categorisation of the demand patterns has not received sufficient academic attention thus far, even though, from the practitioner’s standpoint it is appealing to switch from one estimator to the other according to the characteristics of the demand series under concern. Algebraic comparisons of MSE expressions result in universally applicable (and theoretically coherent) categorisation rules, based on which, “non-normal” demand patterns can be defined and estimators be selected. All theoretical findings are checked via simulation on theoretically generated demand data. The data is generated upon the same assumptions considered in the theoretical part of the thesis. Finally, results are generated using a large sample of empirical data. Appropriate accuracy measures are selected to assess the forecasting accuracy performance of the estimation procedures discussed in the thesis. Moreover, it is recognised that improvements in forecasting accuracy are of little practical value unless they are translated to an increased customer service level and/or reduced inventory cost. In consequence, an inventory control system is specified and the inventory control performance of the estimators is also assessed on the real data. The system is of the periodic order-up-to-level nature. The empirical results confirm the practical validity and utility of all our theoretical claims and demonstrate the benefits gained when Croston’s method is replaced by an estimator developed during this research, the Approximation method.
277

Integrated Pricing and Seat Allowance for Airline Network Revenue Management

Mohan, Baskar 11 July 2005 (has links)
The airline industry is facing unprecedented challenges in generating sufficient revenues to stay in business. Airlines must capture the greatest revenue yield from every flight by leaving no seats unsold and not over filling the cabin with discount fares. To succeed in doing the above airlines must be able to accurately forecast each of their market segments, manage product andprice availability to maximize revenue and react quickly to competitive changes in the market place. Thus seat inventory control and ticket pricing form the two major tools of revenue management. The focus of this paper is to consolidate the ideas of seats inventory control and pricing in order to maximize the revenues generated by an airline network. A continuous time yield management model for a network with multiple legs, multiple fare classes and dynamic price changes for all fare classes is considered. Each fare class has a set of fares from which the optimal fare is chosen based upon the Minimum Acceptable Fare (MAF) which performs the critical role in the decision process. A machine Learning based algorithm, EMSRa based and EMSRb based algorithm for obtaining dynamic policies for combined pricing and allocation. The algorithms are implemented for a sample network with eight cities, eleven logs, thirty origin-destinations(ODs), three fare classes, three levels of fares in each class and ninety itineraries.
278

Lagervärdering och lagerstyrning hos ett litet handelsföretag / Inventory control and valuation in a small retail company

Adielsson, Magnus, Harlos Salmén, Robin, Svensson, Robert January 2010 (has links)
<p>I ett litet företag finns en risk att ledningen fokuserar så mycket på kärnverksamheten att övriga administrativa verksamheter åsidosätts. Exempelvis finns det risk att företaget inte har full kontroll på sina lager.</p><p>Syftet med den här uppsatsen är att beskriva och analysera värderingen och styrningen av lagret hos ett litet handelsföretag med butik och i förekommande fall ge förbättringsförslag.</p><p>Vi har dels studerat lagar och rekommendationer avseende hantering av lager samt litteratur inom området lagerstyrning i handelsföretag. Dessutom har vi intervjuat företrädare för ett typiskt litet handelsföretag.</p><p>Det undersökta företaget uppfyller gällande lagar och rekommendationer, men inte så mycket mer. Vidare använder sig företaget mestadels av känsla och erfarenhet i sin lagerstyrning. Förtaget använder alltså inte formella analyser och metoder i någon större utsträckning, om ens någon. Vi har några förslag på förbättringar i detta avseende.</p> / <p>In a small company there is a risk that the management focuses so much on the core business that other administrative tasks are ignored. For example, there is a risk that the company does not control its inventories efficiently.</p><p>The purpose of this thesis is to describe and analyze the valuing and control of the inventory in a small retail company with a store and, where appropriate, give suggestions for improvement.</p><p>We have studied laws and recommendations regarding inventory valuation and other literature regarding inventory control in retail companies. Additionally we have interviewed representatives for a typical small retail company.</p><p>The investigated company does comply with applicable laws and recommendations, but not much more. Furthermore, the company uses mostly feel and experience in its inventory control. The company does not use formal inventory control in any great extent, if any. We have some suggestions for improvements in this regard.</p>
279

The impact of inventory record inaccuracy on material requirements planning systems /

Bragg, Daniel Jay, January 1900 (has links)
Thesis (Ph. D.)--Ohio State University, 1984. / Includes bibliographical references (leaves 171-177). Available online via OhioLINK's ETD Center.
280

Effektiviserad lagerstyrning av reservdelar inom hjälpmedelsförsörjning / Efficient inventory management of spare parts in the health care sector

Stjärnström, Dan, Sundqvist, Andreas January 2013 (has links)
Syfte – Syftet med denna studie är att undersöka hur lagerstyrning av reservdelar inom hjälpmedelsförsörjning kan effektiviseras. Metod och genomförande – Den valda strategin för att uppfylla studiens syfte omfattades av att genomföra en fallstudie i samarbete med Hjälpmedelscentralen på Länssjukhuset Ryhov i Jönköping. Empiri från fallstudien har erhållits genom intervjuer och dokumentationsstudier. Insamlad data har analyserats gentemot det teoretiska ramverket och därmed genererat studiens resultat. Resultat – Studiens resultat visar inledningsvis på att rörlighet, volymvärde och kritiskhet är viktiga aspekter att beakta vid lagerstyrning av reservdelar inom hjälpmedelsförsörjning. Rörlighet och volymvärde har utgjort kriterier för en sortimentsövergripande ABC-klassificering, vilket resulterade i tre segment. Ett av dessa segment, kundorder, har så pass låg rörlighet att det ansågs lämpligt att endast beställa dessa reservdelar då behov uppstår. För de övriga segmenten bör lagerstyrningen utföras med beställningspunktsystem, dock med en viss skillnad när det gäller styrningens intensitet. Vidare anses det lämpligt att, för enskilda reservdelar, göra kvalitativa bedömningar avseende kritiskhet. Detta ska säkerställa att kritiska reservdelar får en mer uppmärksammad styrning för att därmed, i större utsträckning, undvika bristsituationer. Implikationer – I denna studie har det fastställts hur lagerstyrning av reservdelar inom hjälpmedelsförsörjning kan effektiviseras. För verksamheter som vill åstadkomma detta är det dock nödvändigt att identifiera de aspekter som, för verksamheten i fråga, är mest väsentliga. Vidare krävs det att tillgång till nödvändigt dataunderlag säkerställs. Begränsningar – Fallstudiedesignen utgjordes av en enfallsstudie där endast en analysenhet undersöktes. I och med att olika verksamheter har olika förutsättningar för lagerstyrning hade det varit lämpligt att inkludera fler fallverksamheter i undersökningen. Detta hade resulterat i en högre grad av generaliserbarhet. / Purpose – The purpose of this study is to investigate how to achieve efficient inventory management of spare parts in the health care sector. Methodology – To meet the purpose of the study a case study has been conducted in collaboration with Hjälpmedelscentralen at Länssjukhuset Ryhov in Jönköping. The empirical data have been obtained by methods such as interviews and documentation studies. By analysing empirical data in comparison with the theoretical framework the findings of the study was generated. Findings – Initially, the findings of the study implies that aspects such as usage frequency, annual dollar volume and criticality are important to consider in inventory management of spare parts in the health care sector. Usage frequency and annual dollar volume have been used as criteria for an assortment wide ABC-classification which resulted in three segments. One of these segments, customer order, has a very low usage frequency. Therefore it was considered appropriate to only order these spare parts when an actual need has occurred. The inventory management of the remaining segments should be carried out with a reorder point system. However, there is a certain difference regarding the intensity of the management between the two segments. Furthermore, it’s appropriate to conduct a classification based on criticality. This should ensure that critical spare parts get more attention and hence decreasing the risk of shortage. Implications – In this study, it has been determined how to achieve efficient inventory management of spare parts in the health care sector. For those who aim to do this it’s necessary to identify the aspects that are most important for the particular business. Furthermore, it’s important that these businesses ensure the availability of necessary data. Research limitations – The conducted case study was designed as a holistic single case study. Since businesses differ from each other it would have been appropriate to conduct a multiple case study. As a result of this, a higher degree of generalisation could have been achieved.

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