A indústria brasileira de calçados tem sido profundamente afetada pela pressão da competitividade global causada pela maior abertura do mercado. Ela possui características peculiares de produção. Esta dissertação relata os resultados de incremento de produtividade em uma indústria de calçados orientados pelos princípios da filosofia just in time, de forma especial através do gerenciamento visual da produção e do trabalho em grupos. / The brazilian shoe industry has been deeply affect by the pressure of global competition caused by the opening of our market. It has very peculiar characteristcs concerning the production. This dissertation relate the results to improve productivity in the shoe industry oriented by the principles of just in time philosophy, in a very particular way the implementing of visual management and work groups.

Made available in DSpace on 2015-04-22T22:10:53Z (GMT). No. of bitstreams: 1 pedro paulo.pdf: 2376581 bytes, checksum: 24aaf95c22d20e652da207f291b39f8a (MD5) Previous issue date: 2011-09-16 / A proper inventory management is very important, given the value of the items stored and the association with the operating cycle of a company. Information technology has played a key role in a proper inventory management. Usability, well applied, increases the productivity of users, however, its absence increases the occurrence of errors and dissatisfaction. In order to minimize problems with the tool used in this study case and to fit an appropriate inventory management model, an analysis was performed on the tool used in inventory management, using concepts of usability, data and documentation provided. The problems found ranged from the visual inconsistency in the navigation menus without any standard, too much information polluting and confusing the user, inadequate treatment of errors and lack of feedback. The study focused on the problems found with special focus on treatment and prevention of errors and appropriate return of information to users, in order to propose a web system able to reduce errors and correction procedures, reduction of operating time interface, reducing training costs, maintenance and user support, and consequently, increased efficiency and data reliability. In pursuing this goal, a study was made in order to understand the theory of inventory management and its models, the influence of information technology and how usability can facilitate the use of the system and increase the quality of user experience. As for the methodological approach, this research is classified as qualitative and as to the procedures qualifies as a bibliographical, documentary and field research. The data used in the study were provided by the company relating to the stocks of 2008, 2009 and the first half of 2010. The study shows, in technical and usability terms, that the proposal could generate significant benefits for quality of the report of outcomes, improving performance and efficiency in the use of the system. From the inventory management perspective, the study shows that with a tool capable of providing reliable and accurate data it is possible to gain greater control of inventory through the correct application of Just in Time. / Uma gestão de estoques apropriada é muito importante, dado o valor dos itens armazenados e a associação com o ciclo operacional de uma empresa. A tecnologia da informação tem desempenhado um papel fundamental para uma adequada gestão de estoques. A usabilidade, bem aplicada, aumenta a produtividade dos usuários, contudo, sua ausência, aumenta a ocorrência de erros e a insatisfação. Com o intuito de minimizar os problemas com a ferramenta utilizada neste estudo de caso e para adequar-se a um modelo de gestão de estoques apropriado, foi realizada uma análise da ferramenta utilizada no gerenciamento de estoque, utilizando conceitos da usabilidade, dados e documentos fornecidos. Os problemas encontrados iam desde o visual, inconsistência na navegação com menus sem padrão, excesso de informações poluindo e confundindo o usuário, tratamento inadequado de erros e falta de retorno de informações (feedback). O estudo centrou-se nos pontos negativos encontrados com foco especial no tratamento e prevenção de erros e retorno de informações adequadas aos usuários, com o objetivo de propor um sistema web visando à redução de erros e de procedimentos de correção; redução do tempo de operação da interface; redução de custos de treinamento, de manutenção e de suporte ao usuário e, como consequência, o aumento da eficiência e da confiabilidade nos dados. Ao buscar este objetivo, foi preciso entender a teoria de gestão de estoques e seus modelos, a influência da tecnologia da informação e como a usabilidade pode facilitar o uso do sistema e aumentar a qualidade da experiência do usuário. Quanto à abordagem metodológica, esta pesquisa classifica-se como qualitativa e, quanto aos procedimentos se enquadra como uma pesquisa bibliográfica, documental e pesquisa de campo. Os dados utilizados no estudo foram disponibilizados pela empresa referentes aos estoques de 2008, 2009 e primeiro semestre de 2010. O estudo mostra, do ponto de vista técnico e da usabilidade, que a proposta pode gerar vantagens significativas quanto à qualidade dos resultados esperados dos relatórios e na melhoria no desempenho e eficácia na utilização do sistema. Do ponto de vista da gestão de estoques, mostra que com uma ferramenta confiável e capaz de fornecer dados precisos é possível obter maior controle dos estoques, através da aplicação correta do Just in Time.

Anläggningsarbeten är vägbyggen, markberedning, grundläggning och finplanering av mark. Dessa arbetsområden är ofta trånga och i de fallen behövs en effektiv logistikplanering. Vid anläggningsarbeten krävs ofta ett samspel med många inblandade parter så som husbyggen där flera aktörer är inblandade, eller som vid infrastruktur där det på arbetsplatsen krävs ett samspel mellan arbetsfordon och övriga trafikanter. Ett anläggningsbygge är flexibelt och eventuella komplikationer i arbetet är ibland svårt att förutse. Leveransplaneringen måste fungera för att produktionen ska fortgå, då är det viktigt att veta hur leveranskedjans olika delar ser ut, samt logistikens betydelse för tidplanen. För att förbättringar ska uppnås vid inköp och leveranser spelar leverantören en nyckel roll. Enligt LEAN-metoden ska det tydligt klargöras för leverantörerna hur arbetet ska gå till med leveranser samt att dessa ska hålla sin del i avtalet. Ett arbete med att införa Just In Time-leveranser minskar mängden av lagrat material på arbetsplatsen avsevärt och 5S-rutiner ger en mer säker och strukturerad arbetsplats. / Construction work is road construction, site preparation, foundation and advanced scheduling of land. These areas are often narrow and this cases requires an effective logistics planning. Ground construction is often required interaction with many involved parties such as house building where several actors are involved or in the infrastructure where the workplace requires an interaction between the work vehicles and other road users. The ground construction is flexible and possible complications of the work is sometimes difficult to anticipate. Delivery planning must work for production to proceed and it is important to know how the supply chains different parts look like, as well as the importance of logistics for the time schedule. For improvements to be achieved in purchasing, the suppliers play a key role. According to LEAN method there must clearly be made to the suppliers how the work should be proceed with deliveries and that they have to keep their part of the agreement. Just In Time deliveries reduce the amount of stored material in the workplace significantly and 5S routines provide a more secure and structured workplace.

En stor del av fordonsindustrin tillverkar mot order och använder sig av modulsystem för att effektivt kunna anpassa produkterna efter varierande kundbehov. Ett ökat antal varianter av moduler har bidragit till utvecklingen av just-in-sequence (JIS), ett koncept som har vidareutvecklats från just-in-time och ställer krav på att leveranser sker vid rätt tidpunkt, i rätt mängd, av rätt kvalitet och dessutom i en förbestämd sekvens. Produktionsstopp eller störningar som uppstår i sekvenserna kan orsaka stora kostnader hos kunden, vilket gör leverantören till en viktig aktör. Syftet med studien har i och med detta varit att undersöka hur leverantörer med ett kundorderstyrt produktionsflöde kan säkerställa sekvensleveranser, med fokus på planering och uppföljning. En fallstudie har genomförts på Scania Ferruform i Luleå och mer specifikt på företagets tillverkning av sidobalkar. Företaget genomför uppföljning av produktionen genom att bland annat mäta sekvensriktigheten, vilket speglar hur stor andel av färdigvarulagret som kan levereras i rätt sekvens till kunderna. Risken att störningar uppstår hos kunden, både internt och externt, kan reduceras genom att förbättra sekvensriktigheten. Studien har utifrån detta undersökt hur sekvensriktigheten kan förbättras, med avseende på planering och uppföljning. Planeringen har avgränsats till att främst undersöka körplaneringen, vilken sker efter frisläppning av order till verkstaden. Med hjälp av den upprättade teoretiska referensramen kunde empiriska data analyseras. Först och främst visar slutsatserna på att det finns en tydlig koppling mellan uppföljning och körplaneringen, men även till sekvensriktigheten. Körplaneringen är huvudsakligen operatörsstyrd, dock med grund i en initial körplan. Detta innebär att verkstadspersonalen har stor möjlighet att påverka produktionsordningen utifrån frisläppta order. Ofta sker även detta i syfte att optimera den egna processen, vilket i detta flöde innefattar bland annat minimering av omställningstid, skrotminimering och uppfyllande av nyckeltal. Den automatiska planeringsfunktionen som används har visat sig vara bristfällig och tillsammans med begränsningar i produktionens utformning skapar detta ett behov av att manuellt genomföra körplanering. Slutsatserna kring uppföljning i produktionen är att den i nuläget inte skapar några incitament till att prioritera sekvensriktigheten. Istället finns ett fokus inom produktionen att uppnå det skiftmål som finns, vilket beskriver antalet balkar som bör tillverkas under skiftet. Detta innebär vid tillfälle att den balk som ur sekvensperspektiv bör tillverkas prioriteras bort i syfte att uppnå målet angående antal balkar. Det som även kan konstateras genom studien är det faktum att produktionens utformning många gånger begränsar möjligheten att tillverka enligt sekvens, vilket ibland tvingar fram beslut som inte gynnar sekvensriktigheten. Rekommendationerna till företaget innebär att på kort sikt skapa incitament till att förbättra sekvensriktigheten, genom att införa nyckeltal som är anpassade efter detta. Sekvensriktighet kan införas som ett nyckeltal, men på grund av att procentsiffran kan vara svårtolkad rekommenderas även kompletterande mått. På längre sikt innebär rekommendationerna att utveckla den automatiska funktionen för produktionsplanering. Om denna kan ta hänsyn till de faktorer som leder till manuell körplanering i nuläget, kan detta reducera behovet av att genomföra körplanering i flödets olika processer. I sin tur kan detta skapa förutsättningar för en bättre sekvensriktighet och minskad risk för suboptimering. / A majority of the automotive industry are applying a make-to-order strategy in the manufacturing process. Many of them also use a modular system to efficiently adapt the products to changing customer requirements. An increasing amount of variations of the modules has led to the development of just-in-sequence, a concept that has developed further from just-in-time and that requires deliveries at the right time, in the right amount, of the right quantity and in a predetermined sequence. Disturbances that occur in the sequence can cause problems and high costs for the customer, which increases the role of the supplier. The purpose of the study has therefore been to examine how suppliers with a customer order driven production flow can ensure sequenced deliveries. A case study has been conducted at Scania Ferruform in Luleå and more specifically at the sidemember production unit. The sequence correctness is one measure that is used for monitoring and follow-up, and it reflects the share of the finished good inventory that can be delivered in sequence to the customers. Improving the sequence correctness can decrease the risk of disturbances occurring in the delivery and thereby at the customer, both internally and externally. The study has therefore had the focus of exploring how the sequence correctness can be improved, with regards to planning and monitoring. In this particular study, the planning has been limited to shop planning of production orders only. The empirically collected data were analysed with the theoretical frame of reference as a basis. The conclusions first of all show that there is a distinct connection between the follow-up process and shop planning, but also that these are directly connected to the sequence correctness. The operators in the different processes mainly control the shop planning, although with the basis of an initial plan based on the released orders. This means that the shop floor operators have a great opportunity to affect the production sequence. This planning is often performed in the purpose of optimizing an individual process of choice, which in this production flow involves for example minimizing setup time, minimizing scrap and fulfilling performance measures that are used. The automatic planning function that is used has proven to be inadequate, which creates a need for manually adjusting the sequence planning. When it comes to monitoring and follow-up of the production, the conclusion is that these do not give any incentives for prioritizing the sequence correctness. Instead there is a focus on achieving the goal of the number of sidemembers to be produced during each working shift. At some points, this means that sidemembers that should be produced with regards to the sequence correctness are not prioritized for the purpose of achieving the target of the number of sidemembers produced. Something that can also be stated is the fact that the production and facility layout limits the possibility to produce according to the customer sequence, which sometimes compels decisions that do not facilitate the sequence correctness. The recommendations to the company in short-term is to create incentives to improve the sequence correctness by implementing performance measures in the production that are adapted to this. Sequence correctness can be one of these measures, but measures to complement this are suggested because of the difficulty of interpreting the result. In the long-term however, the automatic production planning function should be developed. The need for adapting the shop plan in the different processes can be reduced if it can automatically take factors into account that today require manual planning. In turn, this can create a possibility of achieving better sequence correctness and reduce the risk of sub optimization.

A indústria brasileira de calçados tem sido profundamente afetada pela pressão da competitividade global causada pela maior abertura do mercado. Ela possui características peculiares de produção. Esta dissertação relata os resultados de incremento de produtividade em uma indústria de calçados orientados pelos princípios da filosofia just in time, de forma especial através do gerenciamento visual da produção e do trabalho em grupos. / The brazilian shoe industry has been deeply affect by the pressure of global competition caused by the opening of our market. It has very peculiar characteristcs concerning the production. This dissertation relate the results to improve productivity in the shoe industry oriented by the principles of just in time philosophy, in a very particular way the implementing of visual management and work groups.

Orientador: Paulo Correa Lima / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-04T03:14:47Z (GMT). No. of bitstreams: 1 Ching_HongYuh_D.pdf: 8715787 bytes, checksum: 17b2ec4f0b38c42e13a3548ca6ede854 (MD5) Previous issue date: 2004 / Resumo: É fato que as organizações tem dificuldade em implementar suas estratégias e atingir os seus objetivos por não dispor de um sistema de mensuração de desempenho que produza informações relevantes para tomada de decisão. Isto ocorre devido a um gap existente entre os objetivos estratégicos da organização e as suas medidas de desempenho. Esta Tese tem como proposta fechar este gap apresentando um modelo de mensuração de desempenho que alinhe o sistema de manufatura enxuta aos objetivos estratégicos do modelo de negocio da organização. Em paralelo, um sistema de manufatura enxuta é desenhado de modo a permitir realizar as dimensões competitivas criando, assim, vantagens diferenciais para a empresa. Medidas de desempenho são associadas aos requisitos funcionais do sistema de manufatura e então alinhadas em uma relação de causa e efeito, assegurando que os objetivos estratégicos sejam alcançados. Para desenvolver o presente modelo de mensuração, seis modelos foram pesquisados e analisados como referencial. Para desenvolver o sistema de manufatura enxuta e as medidas de desempenho, aplicou-se a abordagem denominada de projeto axiomático. Por fim, as medidas de desempenho desenvolvidas neste modelo foram validadas em uma empresa industrial que já utiliza a manufatura enxuta, para comprovar a lógica do modelo proposto, mensurar os resultados obtidos com a produção enxuta e comparar com a situação anterior de produção em massa / Abstract: It is a fact that organizations have difficulty in implementing their strategies and achieving their objectives due to a lack of a performance measurement system that gives relevant information for decision making. This occurs because of a gap between the strategic objectives of the organization and its performance measures. This thesis proposes to elose this gap by presenting a performance measurement model that aligns the lean manufacturing system to the strategic objectives of the organization's business model. At the same time, a lean manufacturing system is designed to enable the accomplishment of the competitive dimensions, creating therefore unique advantages to the company. Performance measures are connected to the functional requirements and aligned in a cause and effect relationship, ensuring that the strategic objectives are accomplished. In order to develop the current performance measurement model, six models were researched and analyzed as a reference. In order to develop a lean manufacturing system and its performance measures the axiomatic design approach was used. Finality, the performance measures developed in this model were validated in an industrial company, which already has a manufacturing system in place, to prove the logic ofthe proposed mode1, to measure the resu1ts achieved with the 1ean manufacturing and to compare with the previous situation of mass production / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica

Orientador: Iris Bento da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-14T12:55:03Z (GMT). No. of bitstreams: 1 Barbosa_MarcioLucianoGoncalves_M.pdf: 9009969 bytes, checksum: b57e8a5f10e2ca0387dd626ea9c925c8 (MD5) Previous issue date: 2009 / Resumo: De uma maneira geral as indústrias estão a cada dia buscando ser mais eficazes no atendimento a seus clientes. Muitas empresas atuam em segmentos em que seu produto ou família de produtos seguem um padrão de manufatura. Diante desse fato verifica-se que as plantas não têm muita diferença, são muito semelhantes, favorecendo a diminuição das diferenças entre os concorrentes tanto no produto quanto nos processos utilizados. O presente trabalho foi realizado utilizando-se o método de pesquisa objetiva exploratória, através de procedimentos bibliográficos, de natureza quantitativa e qualitativa, realizada em campo, com a coleta de dados através do método pesquisa-ação. Tem como objetivo fornecer um método de implementação aplicável, que possibilite a melhoria da manufatura de produtos ou família de produtos por toda a cadeia de fluxo de valor de forma detalhada e estruturada, baseada nos princípios e práticas enxutas. Observou-se em uma fábrica de hidrômetros, objeto de estudo, que se podem aplicar todas as fases do método elaborado na sequência do processo de melhoria: enxugamento, aprimoramento e inovação; proporcionando ganhos significativos no produto final em relação à qualidade e produtividade. Na qualidade alcançou nível quase zero de rejeição, na produtividade diminuição de 65% de seu lead-time e 36% na mão-de-obra direta. Além de outras melhorias aplicadas em equipamentos, dispositivos, layout, métodos de controle da produção, de inspeção, de teste do produto, células de trabalho, entre outros. Dessa forma, o referido estudo abre um canal que possibilita a obtenção de avanços satisfatórios para melhoria da manufatura através do uso dos princípios enxutos, mostrando que o método elaborado aplicado é bastante promissor. / Abstract: In general the industries day by day are searching to be more efficient in customers' attendance. Many companies act in segments where their products or line of products follow a standard manufacturing. Regarding this, we can notice that the plants are similar and they have decreased the difference among competitors, not only in the product but also in the used processes. The present paper was done considering the objective research method, throughout bibliographical procedures, of quantitative and qualitative targets collected in field and the data collected by the research-action method. It aims to supply a method (way) to implement for all purposes and becomes possible the manufacture of products improvement or line of products, including all the activities contained in the value, chain of the process in a structured way; based in the practical and lean principles. It was observed in a plant of manufactures hydrometers, study object, that in can be applied all the phases of the method described in the sequence of improving process are: the reduction, the improvement and the innovation. They also provided significant profits to final product, such as: decreasing the level of rejection almost to zero, reduction in 65% of its leadtime and 36% in the in-house staff, capacity of production equivalent in two turns, considered increase of performance and quality. Beyond the improvement applied in equipment, devices, layout, methods of control production, inspection, test of the product, cells of work, among others. This way, the related study opens a path that obtains of satisfactory advances for improvement of the manufacture through the lean principles, showing that the method elaborated is sufficiently promising. / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica

Common problems at the construction site are logistics problems regarding material delays, handling and transfers. At present, there is a very low use of digital tools in the construction industry. The construction sector has low productivity and high costs, and one reason for this is that the industry has not adopted new technology to streamline its processes.   The purpose of this degree project is to investigate how BIM (building information modeling) can facilitate logistics work (for example, the supply of materials) at the construction site. This by first investigating what problems arise in production and then how BIM is used to mitigate these problems. Thus, come up with suggestions for a working method and routines to increase the use of BIM to facilitate logistics and supply production with materials. The aim of this thesis is to identify contractor and suppliers needs and to suggest improved working methods with BIM in order to improve logistics in the production phase. These are the selected research questions: What material flow information is important to make logistics work during production? How can BIM be used to manage material flow information and thereby improve logistics?   The work carried out with a qualitative methodology where the questions asked were open and open-ended questions. Furthermore, the author used a semi-structured interview method. This study are based on five interviews and the respondents interviewed were from both Norrköping and Kalmar.   The results indicate that the information needed for production to flow in a good way and get the logistics to work is information regarding deliveries should be close to the Just In Time principle. This means that the right material is delivered at the right time in the right place. Because much of the craftsman day is spent waiting for materials. The need of the supplier is to get an order with enough information. This needed to report is an early delivery plan to avoid waiting for materials and supplying production with materials.   The study also shows that BIM is used as a support to facilitate logistics at the construction site through the right model that has a structure that works throughout the process. It is important to enter the correct information regarding quantity, dimensions and number. Furthermore, it can be used by connecting the 3D model to time schedule to plan when it suits best with deliveries and optimize with Just In Time deliveries. Thus, the model is also used when planning workplace disposition plans. Keywords- BIM, construction logistics, Just In Time, waste, supply chain management / Vanligt förekommande problem på byggarbetsplatsen är logistikproblem gällande materialförseningar, hanteringar och förflyttningar. I dagsläget är det väldigt låg användning av digitaliserade verktyg inom byggbranschen. Byggsektorn har låg produktivitet och höga kostnader, en anledning till detta att branschen inte använder sig av ny teknik för att effektivisera processerna.   Syftet med examensarbetet är att undersöka hur BIM kan användas för att minimera logistiska problem på byggarbetsplatsen (exv. materialförsörjningen). Detta genom att först undersöka vilka problem som uppstår i produktionen, sedan se över hur BIM kan nyttjas för att mildra dessa problem. Därmed komma på förslag på arbetssätt och rutiner för att öka användning av BIM för att underlätta logistik och materialförsörjning av produktionen. Målet är att identifiera entreprenörer och leverantörers behov samt föreslå förbättrade arbetsmetoder med BIM för att förbättra logistik i produktionsfasen. Dessa är de utvalda forskningsfrågorna: Vilken materialflödesinformation är viktig för att logistiken ska fungera under produktionen?   Hur kan BIM användas för att hantera materialflödesinformation och därmed förbättra logistiken?   Arbetet utförs med en kvalitativ metodik där frågorna som ställdes var öppna och öppenriktade frågor. Vidare använde författaren sig av semistrukturerade intervjumetod. Denna studie baserades på fem intervjuer och respondenter som intervjuades var både från Norrköping och Kalmar.   Resultatet indikerar att den informationen som behövs för att produktionen ska flöda på ett bra sätt och få logistiken fungera är information gällande leveranser ska vara nära Just In Time principen. Med det menas att rätt material ska levereras på rätt tid på rätt plats. Eftersom stor del av byggarbetarnas dag går åt att vänta på material. Det som behövs för leverantören är att få beställning men tillräcklig med information. Det behövs redovisas är en tidig leveransplan för att undvika väntan på material och försörja produktionen med material.   Studien visar även att BIM kan användas som ett stöd för att underlätta logistiken på byggarbetsplatsen genom rätt modell som har en struktur som fungerar genom hela processen. Det är viktig att mata in rätt information gällande mängd, mått och antal. Vidare kan användas genom att koppla 3D- modellen till tidsplanering för att planera när passar det bäst med leveranser och optimera med Just In Time leveranser. Därmed kan modellen även användas vid planering av arbetsplatsdispositionsplanen. Nyckelord: BIM, bygglogistik, Just In Time, slöseri, supply chain management

Competent and effective material and technical supply of the enterprise largely determines the success of its operation, therefore, the chosen topic seems relevant. The scientific novelty of the dissertation research consists in the development of a methodical approach to organizing the system of material and technical supply of the construction and installation enterprise, which allows choosing the scheme for organizing material flows and placing links of the system based on the proposed classification of the used material resources and equipment, as well as analyzing the regional distribution and features of the objects being built. supply providing in according to the concept of Just-in-time while reducing transport costs, which leads to increased supply efficiency and reduced production cycle. The practical value of the work in the development of the supply system for construction and installation enterprises, which helps to reduce the production cycle, the volume of stored material resources and the amount of transportation costs. The annual economic effect from the application of the proposed approach for an enterprise selected as an object of testing is 8,385 thousand rubles. / Грамотное и эффективное материально-техническое снабжение предприятия во многом определяет успех его функционирования, поэтому выбранная тема представляется актуальной. Научная новизна диссертационного исследования состоит в разработке методического подхода к организации системы материально-технического снабжения строительно-монтажного предприятия, позволяющего на основе предложенной классификации используемых материальных ресурсов и техники, а также анализа регионального распределения и особенностей возводимых объектов выбирать схему организации материальных потоков и размещения звеньев системы снабжения, обеспечивающую снабжение в соответствии с концепцией Just-in-time с одновременным снижением транспортных затрат, что приводит к повышению эффективности снабжения и сокращению производственного цикла. Практическая ценность работы в разработке системы снабжения для строительно-монтажных предприятий, помогающей и сократить производственный цикл, объемы хранимых материальных ресурсов и величину транспортных затрат. Годовой экономический эффект от применения предложенного подхода для предприятия, выбранного в качестве объекта апробации, составляет 8 385 тыс. руб.

Este trabalho apresenta procedimentos que podem ser utilizados na programação da produção em um ambiente JIT. Esses procedimentos deveriam ser utilizados em sistemas clássicos de programação, onde a utilização do sistema kanban é inviável. O caso estudado se baseia em uma única máquina, com datas de entrega múltiplas e com penalidades distintas de adiantamento e de atraso para cada ordem. O objetivo a ser alcançado é a minimização do custo total. Para isso, é utilizado um procedimento de busca denominado beam search, para gerar as seqüências, e um algoritmo de inserção de ociosidade, para definir os programas. O algoritmo utilizado é uma generalização do algoritmo de GAREY et al. (1988) onde as penalidades são distintas para adiantamento e para atraso. O procedimento e o algoritmo são testados em várias condições sendo comparados com regras de despacho e com a função EXP-ET. Quando a função EXP-ET é utilizada com a possibilidade de inserção de ociosidade, o período de ociosidade ótimo é determinado. Assume-se que a dificuldade de solução do problema é dependente de dois parâmetros clássicos: fator de atraso médio e amplitude relativa das datas de entrega. Testes empíricos comparativos são realizados através de simulação computacional, onde se mede o tempo de solução e o valor alcançado pela função objetivo. Os resultados indicam que o desempenho dos vários procedimentos testados é altamente dependente dos dois parâmetros, mostrando que para a escolha de um procedimento apropriado, deve-se primeiramente conhecer o valor dos parâmetros. São fornecidos os resultados encontrados e os códigos computacionais utilizados no estudo. / This work presents some procedures which can be used in production scheduling problems in JIT environments. These procedures may be used in cases of classical production scheduling where the use of the kanban system is infeasible. The case studied is based on a single machine, with multiple due dates, and distinct earliness and tardiness penalties for each job. The objective function is to minimize total cost. A heuristic search procedure known as beam search is used to construct sequences of jobs, and an idleness insertion algorithm is used to obtain schedules. The algorithm used is a generalization of the GAREY et al. (1988) algorithm, where penalties are distinct for earliness and tardiness. The procedure and algorithm are tested in many conditions involving comparisons with dispatching rules and the EXP-ET function. When EXP-ET function is applied with possibility of idleness insertion, the optimal idleness period is provided. It was assumed that problem hardness is dependent on two classical parameters: average tardiness factor and relative range of due dates. Empirical comparative tests are conducted with computational simulation, where computational solution time and objective function value are evaluated. Results indicate that procedures performance is highly dependent on both parameters, showing that is necessary to know parameters values before choosing an appropriate procedure. The detailed results and computational code used in this study are also provided.