Em diversos setores, em especial no automotivo, uma boa gestão dos estoques de peças de reposição tem impacto significativo na satisfação dos clientes e em sua fidelidade aos fabricantes. Neste trabalho foram estudadas diferentes políticas de gestão dos estoques de peças de reposição, para comparar seu desempenho e elaborar recomendações para seu uso. Foram comparados 17 conjuntos de políticas que envolvem diferentes abordagens no registro das demandas (dados individuais de cada pedido versus dados agregados em janelas de tempo semanais e mensais), modelos de previsão (média móvel, Croston modificado SBA) e diferentes formas de modelar a distribuição da demanda durante o Lead-time de ressuprimento (Normal, Gama, Binomial Negativa, composta Poisson-Normal, composta Poisson-Gama). Cada um desses 17 conjuntos de políticas foi simulado sob duas dinâmicas de reparametrização (mensal e semestral) e para quatro objetivos diferentes do nível de serviço (TFR: Target Fill Rate), totalizando 136 simulações para cada item do estoque (SKU). Foram considerados 10.032 SKU\'s de uma montadora de automóveis instalada no Brasil, com um histórico de seis anos de movimentação. Diferentes recomendações foram elaboradas conforme categorização dos itens já existente na literatura. Os resultados apontaram recomendações distintas para cada TFR, incluindo combinações de todas as alternativas estudadas, descartando apenas o uso das distribuições Normal, composta Poisson-Normal e composta Poisson-Gama. Sugere-se que as recomendações sirvam como guia para o uso desses modelos pelos praticantes. / In many areas, including automotive, a good spare parts inventory management can substantially affect customer satisfaction and their loyalty to the brands. Different spare parts inventory control policies were evaluated in this study, aiming to compare their performance and write recommendations for their usage. Seventeen policy sets were compared, including different approaches in recording demand data (individual orders data against time bucket records weekly and monthly), different demand forecasting methods (simple moving average, Syntetos-Boylan-approximation SBA) and different models for demand distribution during lead-time (Normal, Gama, Negative Binomial, compound Poisson-Normal, compound Poisson-Gama). Each policy set was simulated under two revision frequencies (monthly and semi-annually) and four different Target-Fill-Rates (TFR), totalizing 136 simulation runs for each SKU. Database included movement of 10.032 SKU´s during last 6 years from an automaker installed in Brazil. Results pointed different recommendations for existing classification schemes and under each TFR. Recommendations included all studied alternatives, discarding only the usage of Normal, compound Poisson-Normal and compound Poisson-Gama for demand distribution during lead-time. Practitioners are stimulated to use these recommendations as a guideline.

Em diversos setores, em especial no automotivo, uma boa gestão dos estoques de peças de reposição tem impacto significativo na satisfação dos clientes e em sua fidelidade aos fabricantes. Neste trabalho foram estudadas diferentes políticas de gestão dos estoques de peças de reposição, para comparar seu desempenho e elaborar recomendações para seu uso. Foram comparados 17 conjuntos de políticas que envolvem diferentes abordagens no registro das demandas (dados individuais de cada pedido versus dados agregados em janelas de tempo semanais e mensais), modelos de previsão (média móvel, Croston modificado SBA) e diferentes formas de modelar a distribuição da demanda durante o Lead-time de ressuprimento (Normal, Gama, Binomial Negativa, composta Poisson-Normal, composta Poisson-Gama). Cada um desses 17 conjuntos de políticas foi simulado sob duas dinâmicas de reparametrização (mensal e semestral) e para quatro objetivos diferentes do nível de serviço (TFR: Target Fill Rate), totalizando 136 simulações para cada item do estoque (SKU). Foram considerados 10.032 SKU\'s de uma montadora de automóveis instalada no Brasil, com um histórico de seis anos de movimentação. Diferentes recomendações foram elaboradas conforme categorização dos itens já existente na literatura. Os resultados apontaram recomendações distintas para cada TFR, incluindo combinações de todas as alternativas estudadas, descartando apenas o uso das distribuições Normal, composta Poisson-Normal e composta Poisson-Gama. Sugere-se que as recomendações sirvam como guia para o uso desses modelos pelos praticantes. / In many areas, including automotive, a good spare parts inventory management can substantially affect customer satisfaction and their loyalty to the brands. Different spare parts inventory control policies were evaluated in this study, aiming to compare their performance and write recommendations for their usage. Seventeen policy sets were compared, including different approaches in recording demand data (individual orders data against time bucket records weekly and monthly), different demand forecasting methods (simple moving average, Syntetos-Boylan-approximation SBA) and different models for demand distribution during lead-time (Normal, Gama, Negative Binomial, compound Poisson-Normal, compound Poisson-Gama). Each policy set was simulated under two revision frequencies (monthly and semi-annually) and four different Target-Fill-Rates (TFR), totalizing 136 simulation runs for each SKU. Database included movement of 10.032 SKU´s during last 6 years from an automaker installed in Brazil. Results pointed different recommendations for existing classification schemes and under each TFR. Recommendations included all studied alternatives, discarding only the usage of Normal, compound Poisson-Normal and compound Poisson-Gama for demand distribution during lead-time. Practitioners are stimulated to use these recommendations as a guideline.

Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.

<p>This paper analyses the pricing on spare parts. Empirical studies have showed that manufacturers of durable goods make an unproportional large profit on its spare parts in relation to the revenue it generates. It is first showed that according to the standard economic model the price on spare part ought to be zero since the producer include an insurance in the price of the main good. Further it is showed that moral hazard alone do not explain the pricing found in the studies. Finally an analysis of whether consumers with present-biased preferences could be a possible explanation is made. The analysis finds that it is a possibility however somewhat unlikely.</p>

This paper analyses the pricing on spare parts. Empirical studies have showed that manufacturers of durable goods make an unproportional large profit on its spare parts in relation to the revenue it generates. It is first showed that according to the standard economic model the price on spare part ought to be zero since the producer include an insurance in the price of the main good. Further it is showed that moral hazard alone do not explain the pricing found in the studies. Finally an analysis of whether consumers with present-biased preferences could be a possible explanation is made. The analysis finds that it is a possibility however somewhat unlikely.

Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.

Reuse of components as opposed to material recovery, recycling or disposal has been identified as one of the most efficient EOL strategies for products. The concept behind reuse is that some components and subassemblies have a design life that exceeds the life of the product itself. In order for reuse to be successfully implemented as an EOL strategy, a designer needs to incorporate into a product a philosophy of Design for Reuse (DfRe) at the early design stage. Reliable methods to assess the remaining life of used components based on a products usage life are also required. Furthermore, current industry practices and literature advocate that there is no methodology to decide which parameters need to be redesigned so as to change the life of a selected component to a desired level. The objective of this research is to develop a methodology to assess the reuse potential of product groups based on component failure mechanisms and their associated critical lifetime prediction design parameters. Utilising these clustered groups mathematical models were then developed to establish the useful life of the components for each clustered group. Finally, a means of equating useful life to design life was established and the relationship between, the failure mechanisms, critical lifetime prediction design parameters and design life were represented in graphical format. In order to achieve the proposed objective, Cluster analysis, in particular Group Technology (GT) and Hierarchical clustering were employed to group components with similar failure mechanisms. Following this, multiple linear regression was used to establish mathematical models based on condition monitoring data for each of the clustered groups and their related critical lifetime prediction design parameters. A sensitivity analysis was conducted using the mathematical models, in order to produce graphical relations between the useful life and design parameters of a product. The validity of the suggested methodology was tested on electric motors and a gearbox as both these components have demonstrated great reuse potential. The results demonstrate that the methodology can assist designers in estimating the design life and associated design parameters with great accuracy, and subsequently aiding in a stratagem for reuse.

Orientador: Fernando Augusto da Silva Marins / Banca: Jorge Muniz Junior / Banca: Michel Carmem Neyra Belderrain / Resumo: Esta dissertação abordou o problema de disponibilidade de peças de reposição para o atendimento às solicitações dos clientes na pós-venda, principalmente dos setores naval, aéreo e siderúrgico, que participam de um mercado que apresenta características próprias. A falta de determinadas peças de reposição acarreta descontentamento ou, pior, a impossibilidade de utilização do produto. Comumente, o planejamento de estoque não leva em consideração a visão da área de suporte ao cliente, que vivencia os conflitos e efeitos causados por eventuais faltas de peças. Dessa forma, este estudo objetivou propor um modelo que auxilie na decisão gerencial, com respeito ao perfil do estoque de peça de reposição na organização. O estudo partiu do pressuposto de que não é viável estocar todos os tipos de peças de reposição, tendo assim que identificar quais agregam valor. Isso foi feito por meio, de um modelo inclusivo, que combinou o Método de Auxílio à Decisão por Múltiplos Critérios e a Combinação desses critérios. O primeiro, através dos julgamentos de diferentes profissionais, objetivou alcançar um resultado consolidado e priorizado, enquanto que o segundo, através da classificação por combinação sem repetição, buscou encontrar grupos com característica semelhantes priorizados entre si. O modelo conseguiu reduzir a dificuldade de seleção de peças de reposição equilibrando as necessidades das diferentes áreas. / Abstract: This study tackled the problem of spare parts availability for the fulfillment of the after-market customers, mainly the naval, aviation and the steel industries, which are part of a market that has its own characteristics. The lack of certain spare parts causes unpleasant situations for customers or, even worse, the impossibility of utilization of product. Normally, the stock planning does not take into consideration the customer support area experience, which goes through the conflicts and effects caused by eventual lack of parts. Thus, this study envisaged to propose a model which can help in management decisions, regarding the profile of spare part stock in the organization. The study considered that it is not viable to stock all kinds of spare parts, thus having to identify which ones can aggregate value for customer. This was done through an inclusive model, matched the Multiple Criteria Decision Aid and the combination of these criterias. The first, envisaged to reach a consolidated and prioritized result, through the judgment of different professionals, whereas the second, sought to find groups with similar characteristics prioritized among each other, through the classification by combination without repetition. The model got to reduce the difficulties of choosing spare parts balancing the needs of different areas. / Mestre

Made available in DSpace on 2014-06-11T19:30:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-15Bitstream added on 2014-06-13T19:39:25Z : No. of bitstreams: 1 vieira_ha_me_guara.pdf: 406242 bytes, checksum: 5fb852de1f30a52599d87ed826634d4d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esta dissertação abordou o problema de disponibilidade de peças de reposição para o atendimento às solicitações dos clientes na pós-venda, principalmente dos setores naval, aéreo e siderúrgico, que participam de um mercado que apresenta características próprias. A falta de determinadas peças de reposição acarreta descontentamento ou, pior, a impossibilidade de utilização do produto. Comumente, o planejamento de estoque não leva em consideração a visão da área de suporte ao cliente, que vivencia os conflitos e efeitos causados por eventuais faltas de peças. Dessa forma, este estudo objetivou propor um modelo que auxilie na decisão gerencial, com respeito ao perfil do estoque de peça de reposição na organização. O estudo partiu do pressuposto de que não é viável estocar todos os tipos de peças de reposição, tendo assim que identificar quais agregam valor. Isso foi feito por meio, de um modelo inclusivo, que combinou o Método de Auxílio à Decisão por Múltiplos Critérios e a Combinação desses critérios. O primeiro, através dos julgamentos de diferentes profissionais, objetivou alcançar um resultado consolidado e priorizado, enquanto que o segundo, através da classificação por combinação sem repetição, buscou encontrar grupos com característica semelhantes priorizados entre si. O modelo conseguiu reduzir a dificuldade de seleção de peças de reposição equilibrando as necessidades das diferentes áreas. / This study tackled the problem of spare parts availability for the fulfillment of the after-market customers, mainly the naval, aviation and the steel industries, which are part of a market that has its own characteristics. The lack of certain spare parts causes unpleasant situations for customers or, even worse, the impossibility of utilization of product. Normally, the stock planning does not take into consideration the customer support area experience, which goes through the conflicts and effects caused by eventual lack of parts. Thus, this study envisaged to propose a model which can help in management decisions, regarding the profile of spare part stock in the organization. The study considered that it is not viable to stock all kinds of spare parts, thus having to identify which ones can aggregate value for customer. This was done through an inclusive model, matched the Multiple Criteria Decision Aid and the combination of these criterias. The first, envisaged to reach a consolidated and prioritized result, through the judgment of different professionals, whereas the second, sought to find groups with similar characteristics prioritized among each other, through the classification by combination without repetition. The model got to reduce the difficulties of choosing spare parts balancing the needs of different areas.

El presente trabajo de investigación desenvuelve una propuesta de comercialización de repuestos alternativos para maquinaria de construcción con características diferenciadas en términos de diseño y fabricación del producto dentro del segmento del mercado alternativo; brindando piezas mecánicas de encaje perfecto para maquinaria, esto se traduce sustancialmente en la mejora del rendimiento de la maquinaria. En el ambiente de las medianas y pequeñas constructoras, los repuestos alternativos son requeridos cuando el equipo mecánico ha llegado a alcanzar las horas de trabajo dentro de la garantía original; y a partir de este punto en el tiempo de vida de la maquinaria se comienzan a analizar “eficiencia en costos”, originándose la posibilidad del uso del alternativo frente al original y para ello cobra importancia, accesibilidad, la inmediatez, la disponibilidad y precio del repuesto. El segmento de clientes objetivo se caracteriza por dueños de equipo de construcción del líder mundial en maquinaria pesada que operan en proyectos de pequeña o mediana envergadura, quienes hoy se encuentran tomando decisiones a corto plazo sobre la manera de cómo mantener sus equipos, ellos no buscan una reconstrucción completa de sus equipos con partes premium, ellos encuentran mayor valor en la prontitud de arreglar el equipo para volver a trabajar, estas decisiones a menudo están íntimamente relacionadas con presiones internas para atender el flujo de caja y metas mensuales de su negocio. Este segmento de clientes adquiere actualmente repuestos alternativos experimentando insatisfacción por la baja calidad de los productos existentes en el mercado peruano. Para este segmento, la propuesta ofrece el mayor rendimiento que se puede brindar al “Equipo Clásico” empleando piezas de encaje perfecto de gran fiabilidad y confiabilidad con una disponibilidad garantizada a través de una red de distribuidores que serán ubicados a nivel nacional y todo a un costo razonable por los repuestos alternativos. El mercado potencial está compuesto por todos los clientes que poseen equipos de la marca líder en maquinaria pesada clásico (antigüedad mayor a 10 años), que para un parque más de 1,500 equipos representan un potencial de mercado estimado mayor a 7 MM USD; de otro lado el mercado meta está compuesto por el 30% de los clientes del mercado potencial que se alcanzará el 3er año con una oportunidad estimada mayor a los 2MM USD. Los proveedores que operan en el mercado actual de partes y repuestos alternativos se encuentran atomizados y dispersos, en este contexto no existe una marca líder del segmento; esto representa una clara oportunidad para la compañía líder nacional en maquinaria pesada puesto que además del producto ofrecido, puede usar el respaldo que lo caracteriza para conseguir penetrar y posicionarse en el segmento a través del lanzamiento de repuestos ALOR. La inversión para puesta en marcha del negocio es de 800,000 USD, siendo que el financiamiento en deuda corresponde al 62.5%, el destino de las inversiones será en activo tangible relacionadas principalmente con la locación y preparación de las tiendas en los principales conglomerados de repuestos del país y el nivel de stock inicial. Se ha logrado demostrar que el negocio es rentable analizando sus principales indicadores y ello conlleva a que es perfectamente factible continuar con el proceso de expansión del negocio abriendo nuevos puntos de venta en el país; sin embargo; este análisis no forma parte del alcance del desarrollo del presente trabajo de investigación. Es así que para un escenario moderado de proyecciones del flujo de caja del negocio que considera una inflación del 2.5% y un crecimiento del 20% anual de las ventas; tenemos un periodo de retorno de la inversión de 5 años. En la evaluación financiera realizada, obtenemos un Valor Actual Neto de $ 576,184.00, además de una Taza Interna de Retorno del 18% que sobrepasa la tasa de descuento utilizad; lo que nos demuestra que el emprendimiento resulta rentable al superar los ingresos a sus egresos durante los siguientes 5 años futuros. / This research paper develops a proposal for the commercialization of alternative spare parts for heavy construction machinery with the characteristics of differentiation in terms of product design and manufacturing within the segment of the alternative market; providing perfect fit mechanical parts for machinery, this translates substantially into improving the performance of the machinery. In medium and small construction companies, alternative spare parts are required when machinery has reached the working hours within the original warranty; and from this point in the lifetime of the machinery medium and small construction companies begin to analyze "cost efficiency", leading the possibility of using the alternative spare parts against the genuine and for this it becomes important, accessibility, immediacy, availability and price of spare parts. The target customer segment is characterized by construction machinery owners of the world leader in heavy machinery operating on small or medium-sized projects, who are today making short-term decisions on how to keep their machinery, they don't seek a complete overhaul of their machinery with premium parts, they find greater value in the promptness of fixing the machinery to get back to work, these decisions are often closely related to pressures to meet cash flow and monthly business goals. This segment of customers currently acquires alternative spare parts experiencing dissatisfaction with the low quality of existing products in the Peruvian market. For this segment, the proposal offers the highest performance that can be provided to the "Classic Machinery" using perfect fit spare parts of great reliability with guaranteed availability through a network of distributors that will be located nationwide and all of this at a reasonable cost for alternative spare parts. The potential market is made up of all customers who own machinery from the leading brand in classic heavy machinery (older than 10 years), which for a park of more than1,500 equipment represents an estimated market potential greater than USD 7 MM; on the other hand the target market is made up of 30% of the potential market customers who will reach the 3rd year with an estimated opportunity greater than 2MM USD. The suppliers that operate in the current market of alternative spare parts are atomized and dispersed, in this context there is no leading brand in the segment; this represents a good opportunity for the national leader in heavy machinery company since in addition of the product offered, it can use the support that characterizes it to get penetrated and positions in the segment through the launch of ALOR spare parts. The investment for start-up of the business is 800,000 USD, with debt financing being 62.5%, the destination of the investments will be tangible assets related mainly to the location and preparation of the stores in the main conglomerates of country spare parts and initial stock level. It has been possible to demonstrate that the business is profitable by analyzing its main indicators and this means that it is perfectly feasible to continue the process of expanding the business by opening new points of sale in the country; however; this analysis is not part of the scope of the development of this research paper. Thus, for a moderate scenario of business cash flow projections that considers inflation of 2.5% and 20% annual sales growth; we have a 5-year return on investment period. In the financial evaluation, we obtain a Net Present Value of $576,184.00, which shows us that entrepreneurship is profitable by surpassing the income to its egress for the next 5 years. In addition, an Internal Rate of Return of 18% that exceeds the discount rate used. / Trabajo de investigación