In this thesis, competitive and cooperative newsboy problems for two substitutable products are analyzed by using game theoretic concepts. The demands of the products are assumed to be dependent and normally distributed. Competition is handled for Nash and Stackelberg games. Nash and Stackelberg games are compared in terms of the order quantities and the expected profits. Cooperative newsboy problem is analyzed for the products having equal costs and revenues. The effect of demand correlation on the order quantities and the expected profits in all of the games is investigated through numerical experiments. Optimal solutions of the Nash, Stackelberg and the cooperative games are examined analytically when the demand correlation is 1.

Submitted by Livia Mello (liviacmello@yahoo.com.br) on 2016-10-11T20:12:25Z No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-21T12:58:59Z (GMT) No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-21T12:59:07Z (GMT) No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) / Made available in DSpace on 2016-10-21T12:59:15Z (GMT). No. of bitstreams: 1 DissTSK.pdf: 3524235 bytes, checksum: 7f004fb5c47d3a888f9b19f884f38946 (MD5) Previous issue date: 2016-05-19 / Não recebi financiamento / This dissertation studies the application of a periodic review inventory model based on the multiperiod newsboy problem, as an effective alternative to reach a well balanced inventory planning policy of subcontractors primary parts area of the aerospace industry. In Brazil, the aerospace industry is responsible for a large amount of the country exports and this industry competes with other globally aerospace supply chains in a scenario increasingly turbulent and demanding for fast deliveries, with high quality levels and low cost. The purpose of this work is to study and propose this alternative for optimizing the inventory planning by means of a quantitative approach, applied in a primary parts sector of the aerospace industry, it will focus in a specific group of items with high annual demand value. The main objective of this approach is to balance the high inventory costs with a high service level demanded in this industry, and efficiently respond the stakeholders expectations, with superior performance of the usual models adopted by this industry, and give a better support to the decision makers in a tactical-operational level. The result obtained show the potential of the method to improve the performance of these inventory management and planning systems. / Este trabalho estuda a aplicação de um modelo analítico de revisão periódica de estoques, baseado no problema do jornaleiro multiperíodo (Multiperiod Newsboy Problem), como uma alternativa efetiva para determinação da política de planejamento de estoques do setor de peças primárias subcontratadas da indústria aeroespacial. No Brasil, a indústria aeroespacial é responsável por grande parte das exportações do país e compete globalmente com outras cadeias aeroespaciais num cenário cada vez mais turbulento e exigente por entregas rápidas, com altos níveis de qualidade e baixos custos. O objetivo deste trabalho é estudar e propor essa alternativa para otimizar o planejamento de estoques por meio de uma abordagem quantitativa, aplicada no setor de peças primárias da indústria aeroespacial, para um grupo de peças com características especificas, principalmente as de alto valor para demanda anual. O intuito desta abordagem é equilibrar os altos custos de estoque com os altos níveis de serviço exigidos por esta indústria, e responder de forma eficiente às expectativas dos stakeholders, com desempenho superior aos modelos atualmente utilizados no setor e auxiliar de forma mais precisa e sistematizada a tomada de decisão no nível tático-operacional. Os resultados obtidos mostram o potencial do método para melhorar o desempenho desses sistemas de gestão e planejamento de estoques.

Le management de la chaîne logistique concerne un large éventail d’activités. Nombreuses ceux qui ont un caractère incertain apportant souvent des conséquences inattendues. Malgré cela, l’incertitude est fréquemment non considérée dans la gestion de la chaîne logistique traditionnelle. En plus de l’incertitude, l’indisponibilité des ressources augmentera la complexité du problème. En prenons en compte les contraintes d’incertitude et de disponibilité nous étudions le management de la chaîne logistique selon différents aspects. Cette thèse représente une tentative de recherche afin d’aborder ce problème d’une façon systématique et complète et nous espérons que notre travail contribuera aux futurs travaux de recherche et sera utile aux gestionnaires de la chaîne logistique. Nous nous concentrons sur trois sources classiques de l’incertitude ; celle de la demande, celle la fabrication et celle liée à la distribution. Pour chaque source d’incertitude, nous analysons ses causes et ses impacts sur les performances de la chaîne logistique. L’incertitude est spécifiée dans des problèmes classiques concrets et des approches sont proposées pour les résoudre. Nous nous sommes également focalisés sur le problème bi-niveau de vendeur de journaux qui représente une chaîne logistique miniature, concerné par une double incertitude. Les méthodes utilisées offrent une bonne démonstration du traitement des variables incertaines dans les problèmes de décision / Supply chain management involves a wide range of activities. Among most of them, uncertainty exists inherently and always brings some consequence not expected. However, uncertainty is not considered much in conventional supply chain management. In the case where availability of resources is not what we expect, complexity of supply chain management increases. Taking constraints of uncertainty and availability into account, we aim to discuss supply chain management from different aspects. This thesis is an attempt of systematic and complete research from this point and we would like to offer some references to researchers and managers in supply chain. We focus on three classic sources of uncertainty: demand, manufacturing and distribution. For each source of uncertainty, we analyze its cause and its impact to the performance of the supply chain. Uncertainty is specified into concrete classic problem and an approach is proposed to solve it. Furthermore, bi-level newsboy problem as a miniature of supply chain, is focused under double uncertain environment. Treating uncertain variables is actually a treatment on operational level. The methods used offer good demonstration in treating uncertain variables in decision problems

L'objectif de cette recherche est de développer des modèles aussi bien conceptuels, analytiques et managériaux en analysant un maillon de la supply chain, à savoir la relation entre un distributeur et deux fournisseurs opérant dans un environnement incertain. Dans la première partie de la thèse, nous considérons un seul produit, plutôt haut de gamme et/ou périssable, et nous faisons l’analyse sur un horizon d’une période. Dans ce cas précis, les caractéristiques unitaires du produit sont toutes non linéaires, à savoir : le prix, le coût de production, le coût de rupture, le coût de reprise. La demande est supposée être une variable aléatoire. Dans la deuxième partie de la thèse, nous nous inspirons des pratiques de firmes internationales qui s’approvisionnent, pour une partie de leur offre, dans des pays à bas coûts. Nous développons plusieurs modèles mais dont la structure de base est similaire, à savoir : deux produits (un haut gamme acheté localement et l’autre bas de gamme acheté dans les pays à bas coûts), un horizon de trois périodes, deux fournisseurs à capacité de production limitée et un distributeur ayant des capacités de stockage limitées. Une panoplie de résultats théoriques, numériques ainsi que des insights sont présentés.Les modèles développés peuvent être utilisés comme des outils d’aide { la prise de décision dans les environnements décrits dans cette thèse / The objective of this research is to develop conceptual, analytical, and managerial models and insights by analyzing a portion of the supply chain made up of a retailer dealing with two suppliers in an uncertain environment. In the first part of this thesis, we consider a single high-end (or perishable) product, single period, variable unit price, variable unit production cost, variable unit shortage cost, variable unit salvagevalue, stochastic demand problem. In a second part of the thesis, we consider settings inspired by the case of large international companies sourcing some of their products from low cost countries. This structure is as follows: two products (one sourced locally and the other sourced abroad), a three-period, two-stages, two capacitated suppliers, and a single capacitated retailer. Both analytical and numerical results are provided. Important theoretical results and insights are developed for these types of settings. These models can be used as decision-making aid tools in such environments