No / This paper presents a stochastic automaton approach to stock ordering for retailers of time-limited goods, in the modern supply chain network. The rationale applied is that by ordering in small quantities frequently, overstocking will be reduced, capital liquidity improved and wastage limited. A consequence for the complete supply chain is that such an approach could substantially minimise the reactive bullwhip effect, leading to more efficient utilisation, production and agility throughout the chain. Such agility and flexibility can only be achieved by full integration of stock inventory monitoring technologies (such as RFID) with enterprise integration systems (such as ERP) connected to suppliers, mediated by the internet. We undertake a comparative simulation study of stock ordering using a stochastic automaton and a naive traditional approach. This shows that stochastic ordering, prompted by a stochastic automaton, exhibits characteristic properties that are a prerequisite for reducing the bullwhip effect, thus enabling agile inventory management.

In vehicle industry, it has been trends towards focusing on pull-basedsystems and elimination of waste (Lean), which decrease the tied-up capitallevel in the focal factory. Research by Holweg & Miemczyk (2002)showed that the relevant supply chain has low inventory level in the focalfactory, but at upstream and especially downstream; the tied-up capitallevel is dramatically higher in comparison to the focal factory.By conducting research and extensive literature reviews, this volatilityof tied-up capital level has been studied and analysed with regard topush and pull systems. As the three main causes of this unevenness; bullwhipeffect, CODP position in supply chain and intensity level of supplierrelationship have been identified and explained.As a practical solution for decreasing the tied-up capital level of finishedvehicles, implementation of centralised warehouse structure hasbeen suggested and discussed.Moreover, as an application of game theory in logistics, iterated prisoners’dilemma has been discussed as the base for a progressive relationshipwith suppliers (upgrading to win-win game) which is requisite for the successof pull-based supply chains. / Program: BSc in Industrial Engineering - International Business Engineering

Wiss. Hochsch. für Unternehmensführung, Diss.--Vallendar, 2004.

No description available.

Globalization and the surge of competition across industries forced companies to improve their supply chain capabilities to serve their customers efficiently and effectively. Due to this fact, businesses are no longer capable of handling all supply chain operations without collaboration and coordination with other firms. One of the key obstacles to coordination is the lack of information sharing and trust between firms since they view information as a sensitive asset. Digital technologies like blockchain, with its inherited features, have the capability to facilitate real-time information sharing, solve trust issues, and improve end-to-end visibility across the supply chain. This licentiate thesis highlights the impact of multiple aspects of information sharing on the bullwhip effect mitigation and explores the potential of blockchain technology as a new coordination mechanism for reducing information distortions, enhancing trust, and orchestrating decision making. Three research papers have been produced within this context and are appended to the thesis. Paper A presents an information sharing-based blockchain architecture to mitigate the bullwhip effect in service supply chains. Paper B aims to explores the literature in terms of using multiple aspects of information sharing to lessen the bullwhip effect. Finally, Paper C introduces an agent-based modeling and simulation approach for two aspects of information sharing: “what to share” and “how to share.” The results show that blockchain technology does provide a significant solution to trust-based issues and information sharing visibility considering the bullwhip effect mitigation. The results also provide a guide for supply chain managers to achieve better coordination and serve as a roadmap for supply chain researchers.

This dissertation is a collection of essays on challenges in international trade and international finance, which apply econometric methods to diverse data sets and relate them to economic policy questions. In times of crises, the question, whether individual countries have the ability to pursue idiosyncratic monetary policy, is important. The degree of integration and comovement between financial markets, for instance, is critical to better assess the real threat facing a country in a crisis. Also, from a macroeconomic modeling perspective, there has recently been a renewed interest in the cyclical and long-run comovement of interest rates. Hence, in a first essay, we reinvestigate the long- and short-run comovements in the G7-countries by conducting tests for cointegration, common serial correlation and codependence with nominal and real interest rates. Overall, we only find little evidence of comovements: common trends are occasionally observed, but the majority of interest rates are not cointegrated. Although some evidence for codependence of higher order can be found in the pre-Euro area sample, common cycles appear to exist only in rare cases. We argue that some earlier, more positive findings in the literature are difficult to reconcile due to differing assumptions about the underlying stochastic properties of interest rates. Hence, we conclude that they cannot be generalized for all interest rates, time periods, and reasonable alternative estimation procedures. This finding indicates that scope for individual countries to pursue stabilization policy does still exist in a globalized world. Emerging economies, in general, are much more exposed and vulnerable to crises than industrialized countries. Accordingly, stabilization policy is especially important in these countries and the selection of the best monetary regime is essential. This is why, in a second essay, we contrast two different views in the debate on official dollarization: the Mundell (1961) framework of optimum currency areas and a model on boom-bust cycles by Schneider and Tornell (2004), who take account of credit market imperfections prevalent in middle income countries. We highlight the strikingly different role of the exchange rate in the two models. While in the Mundell framework the exchange rate is expected to smooth the business cycle, the second model predicts the exchange rate to play an amplifying role. We empirically evaluate both models for eight highly dollarized Central American economies. We document the existence of credit market imperfections and find that shocks from the exchange rate indeed amplify business cycles in these countries. Using a new method proposed by Cubadda (1999 and 2007), we furthermore test for cyclical comovement and reject the hypothesis that the selected countries form an optimum currency area with the United States according to the Mundell definition. In the context of the recent global crisis, globalization and vertical integration in particular were often blamed for being the cause for the severe trade crisis. For that reason, in the essay that contributes to the trade literature, we analyze the role of international supply chains in explaining the long-run trade elasticity and its short-term volatility in the context of the recent trade collapse. We adopt an empirical strategy based on two steps: first, stylized facts on long- and short-term trade elasticity are derived from exploratory analysis and formal modeling on a large and diversified sample of countries. Then, we derive observations of interrelated input-output matrices for a demonstrative sub-set of countries. We find evidence for two supply chain related factors to explain the overshooting of trade elasticity during the 2008-2009 trade collapse: the composition and the bullwhip effect. However, evidence for a magnification effect could not be found. Overall, we do not accept the hypothesis that international supply chains explain all by themselves the changes in trade-income elasticity.

[ES] Los productos perecederos representan un gran parte de los bienes que se comercializan en el mundo. Éstos productos empiezan a tener un papel más relevante dadas las condiciones de seguridad alimentaria que requiere la humanidad, en el año 2023 la población del planeta superó los 8 mil millones de habitantes, una cifra que presiona aún más el riesgo alimenticio del planeta. La gestión de éste tipo de cadenas de suministros es responsable en parte de la seguridad alimentaria de las personas, actualmente uno (1) de cada tres (3) kilos de comida que se producen en el mundo se pierde o desperdicia. Ésta situación merece un análisis más profundo, y por tanto se requiere dividir el problema en varias partes para saber la conexión del problema. Encontramos que el efecto látigo, un fenómeno que amplifica la demanda aguas arriba de la cadena de suministros, es responsable en cierto modo de ésta pérdida y desperdicio de alimento. Nuestra investigación encontró que existen varias causas que generan el efecto látigo, como la gestión de la demanda, el tiempo de entrega o de reabastecimiento, nivel de deterioro del producto, entre otros. Éstas causas del efecto látigo fueron simuladas en una cadena de 10 retailers, una central de abastos, tres intermediarios rurales y 6 agricultores; con el fin de evidenciar el impacto en el inventario, el desperdicio y el nivel de servicio de una cadena de suministros del banano. Para la simulación diseñamos un modelos de previsión de demanda Prophet, el cual tuvo en cuenta la tendencia y estacionalidad de la demanda del banano, y el tiempo de entrega y de reabastecimiento de los proveedores. Nuestro modelo logró disminuir el efecto látigo en casi una cuarta parte con respecto a un modelo de previsión básico (Naïve), también redujo el inventario en toda la cadena de suministros del banano en casi tres veces con relación al modelo Naïve. Éstos resultados fueron consistentes en todos los escenarios donde se tuvo en cuenta el nivel de desperdicio del banano, cambios en los tiempos de entrega y de reabastecimiento. Nuestro mayor aporte a la investigación fue diseñar un modelo de previsión basado en Prophet, que no se había usado para disminuir el efecto látigo en una cadena de perecederos, evidenciando que el nivel de deterioro del producto afecta en mayor medida el inventario en la cadena de suministros, en comparación con el tiempo de entrega y de reabastecimiento. Los aportes y hallazgos encontrados en la investigación, deben ser ampliados hacia nuevas líneas, que involucren el comportamiento humano como causa del efecto látigo, otro tipo de alimentos que tengan mayor nivel de vida útil, y estructuras de cadenas que tengan variaciones en sus pedidos, tiempos de producción y capacidades organizacionales / [CA] Els productes peribles representen una gran part dels productes venuts al món. Aquests productes comencen a tenir un paper més rellevant donades les condicions de seguretat alimentària que requereix la humanitat. El 2023, la població del planeta va superar els 8.000 milions d'habitants, una xifra que pressiona encara més el risc alimentari del planeta. La gestió d'aquest tipus de cadenes de subministrament és en part responsable de la seguretat alimentària de les persones; actualment es perd o es malgasta un (1) de cada tres (3) quilos d'aliments produïts al món. Aquesta situació mereix una anàlisi més profunda, i per tant cal dividir el problema en diverses parts per conèixer la connexió del problema. Hem trobat que l'efecte fuet, un fenomen que amplifica la demanda aigües amunt de la cadena de subministrament, és una mica responsable d'aquesta pèrdua i malbaratament d'aliments. La nostra investigació va trobar que hi ha diverses causes que generen l'efecte fuet, com ara la gestió de la demanda, el temps de lliurament o reposició, el nivell de deteriorament del producte, entre d'altres. Aquestes causes de l'efecte fuet es van simular en una cadena de 10 minoristes, un centre de subministrament, tres intermediaris rurals i 6 agricultors; per tal de demostrar l'impacte en l'inventari, els residus i el nivell de servei d'una cadena de subministrament de plàtan. Per a la simulació vam dissenyar un model de previsió de la demanda del Profeta, que tenia en compte la tendència i l'estacionalitat de la demanda de plàtan, i el temps de lliurament i reposició dels proveïdors. El nostre model va aconseguir reduir l'efecte fuet en gairebé una quarta part en comparació amb un model bàsic de previsió (Naïve), també va reduir l'inventari a tota la cadena de subministrament de plàtan gairebé tres vegades en comparació amb el model Naïve. Aquests resultats van ser coherents en tots els escenaris on es va tenir en compte el nivell de residus de plàtan, els canvis en els temps de lliurament i reposició. La nostra major contribució a la investigació va ser dissenyar un model de previsió basat en Prophet, que no s'havia utilitzat per reduir l'efecte fuet en una cadena perible, demostrant que el nivell de deteriorament del producte afecta en major mesura l'inventari de la cadena de subministrament. subministraments, en comparació amb el temps de lliurament i reposició. Les contribucions i troballes que es troben a la investigació s'han d'ampliar cap a noves línies, que impliquen el comportament humà com a causa de l'efecte fuet, altres tipus d'aliments que tenen un nivell més alt de vida útil i estructures de cadena que tenen variacions en els seus ordres, temps de producció i capacitats organitzatives / [EN] Perishable products represent a large part of the goods traded in the world. Given the food security conditions required by humanity, these products are beginning to play a more relevant role; in 2023, the world's population exceeded 8 billion inhabitants, putting even more pressure on the planet's food risk. This type of supply chain management is partly responsible for people's food security. One (1) of every three (3) kilos of food produced worldwide needs to be recovered or used. This situation deserves a more profound analysis; therefore, it is necessary to divide the problem into several parts to know the connection of the problem. We found that the bullwhip effect, a phenomenon that amplifies the demand upstream of the supply chain, is responsible in some way for this loss and waste of food. Our research found that several causes generate the bullwhip effect, such as demand management, delivery or replenishment time, and level of product deterioration. These causes of the bullwhip effect were simulated in a chain of 10 retailers, a supply center, three rural intermediaries, and six farmers to demonstrate the impact on a banana supply chain's inventory, waste, and service level. For the simulation, we designed a Prophet demand forecasting model, which considered the trend and seasonality of banana demand and suppliers' delivery and replenishment time. Our model managed to reduce the bullwhip effect by almost a quarter compared to a basic forecasting model (Naïve), and it also reduced inventory in the entire banana supply chain by almost three times compared to the Naïve model. These results were consistent in all scenarios where the level of banana waste, changes in delivery, and replenishment times were considered. Our most significant contribution to the research was to design a forecasting model based on Prophet, which had not been used to reduce the bullwhip effect in a perishable goods chain, showing that the level of product deterioration affects inventory in the supply chain to a greater extent, compared to delivery and replenishment time. The contributions and findings found in the research should be extended to new lines involving human behavior as a cause of the bullwhip effect, other types of foods with a longer shelf life, and chain structures with variations in their orders, production times, and organizational capacities. / Durán Peña, JA. (2024). Diseño de un modelo de previsión de demanda para reducir el efecto látigo en una cadena de suministros de perecederos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/210911