CAD Based Electric Transporter Path Planning and Production Storage Optimization Using Genetic Algorithm – Industrial Case Study

Štore Steel Ltd. is one of the largest flat spring steel producers in Europe. There are two production lines after rolling – one for flat bars and the other for round bars. The flat bars production generally consists of visual examination, straightening and cutting operation. In addition, heat treatment or magnetic particle testing could be conducted. On the other hand, the round bars production consists generally of straightening, automatic control line control, chamfering and cutting. In addition, heat treatment is possible. For manipulation of the material in the rolling plant, the electric transporter and several cassettes are used. In the paper path planning and production storage optimization (i.e. storage spaces for cassettes) were conducted using genetic algorithm. The production storage is actually the space between main transport passage and individual operations. In the research the universal system using CAD geometry is presented where AutoCAD environment and in-house developed AutoLISP system were used. The production storage – storage spaces for cassettes (location and orientation) with corresponding electric transporter trajectories are represented as CAD objects and thus form individual solution/organism. The organisms undergo simulated evolution. The results of the evolution are compared with actual production storage in the steel plant

Hybrid Algorithm for Solving the Quadratic Assignment Problem

The Quadratic Assignment Problem (QAP) is a combinatorial optimization problem; it belongs to the class of NP-hard problems. This problem is applied in various fields such as hospital layout, scheduling parallel production lines and analyzing chemical reactions for organic compounds. In this paper we propose an application of Golden Ball algorithm mixed with Simulated Annealing (GBSA) to solve QAP. This algorithm is based on different concepts of football. The simulated annealing search can be blocked in a local optimum due to the unacceptable movements; our proposed strategy guides the simulated annealing search to escape from the local optima and to explore in an efficient way the search space. To validate the proposed approach, numerous simulations were conducted on 64 instances of QAPLIB to compare GBSA with existing algorithms in the literature of QAP. The obtained numerical results show that the GBSA produces optimal solutions in reasonable time; it has the better computational time. This work demonstrates that our proposed adaptation is effective in solving the quadratic assignment problem

Hybrid Optimisation Method for the Facility Layout Problem

International audienc

Ant Colony Optimization For Multiobjective Buffers Sizing Problems

International audienc

Traffic Flow Analysis Based on Queuing Models

One of the most important issues in the plant layout design especially in mass production organizations with high inter-plant logistics is‘material flow and inter-plant traffic analysis and its effects on the production capabilities or pauses in production lines. In this paper the inter-plant traffic analysis issue on the basis of single channel queue model (M/M/1) is analyzed in a carmaker company (IKCO). Through the analysis, the production stop rate and relevant costs are estimated

Heuristics and Metaheuristics Approaches for Facility Layout Problems: A Survey

Facility Layout Problem (FLP) is a NP-hard problem concerned with the arrangement of facilities as to minimize the distance travelled between all pairs of facilities. Many exact and approximate approaches have been proposed with an extensive applicability to deal with this problem. This paper studies the fundamentals of some well-known heuristics and metaheuristics used in solving the FLPs. It is hoped that this paper will trigger researchers for in-depth studies in FLPs looking into more specific interest such as equal or unequal FLPs

Dynamic Facility Layout for Cellular and Reconfigurable Manufacturing using Dynamic Programming and Multi-Objective Metaheuristics

The facility layout problem is one of the most classical yet influential problems in the planning of production systems. A well-designed layout minimizes the material handling costs (MHC), personnel flow distances, work in process, and improves the performance of these systems in terms of operating costs and time. Because of this importance, facility layout has a rich literature in industrial engineering and operations research. Facility layout problems (FLPs) are generally concerned with positioning a set of facilities to satisfy some criteria or objectives under certain constraints. Traditional FLPs try to put facilities with the high material flow as close as possible to minimize the MHC. In static facility layout problems (SFLP), the product demands and mixes are considered deterministic parameters with constant values. The material flow between facilities is fixed over the planning horizon. However, in today’s market, manufacturing systems are constantly facing changes in product demands and mixes. These changes make it necessary to change the layout from one period to the other to be adapted to the changes. Consequently, there is a need for dynamic approaches of FLP that aim to generate layouts with high adaptation concerning changes in product demand and mix. This thesis focuses on studying the layout problems, with an emphasis on the changing environment of manufacturing systems. Despite the fact that designing layouts within the dynamic environment context is more realistic, the SFLP is observed to have been remained worthy to be analyzed. Hence, a math-heuristic approach is developed to solve an SFLP. To this aim, first, the facilities are grouped into many possible vertical clusters, second, the best combination of the generated clusters to be in the final layout are selected by solving a linear programming model, and finally, the selected clusters are sequenced within the shop floor. Although the presented math-heuristic approach is effective in solving SFLP, applying approaches to cope with the changing manufacturing environment is required. One of the most well-known approaches to deal with the changing manufacturing environment is the dynamic facility layout problem (DFLP). DFLP suits reconfigurable manufacturing systems since their machinery and material handling devices are reconfigurable to encounter the new necessities for the variations of product mix and demand. In DFLP, the planning horizon is divided into some periods. The goal is to find a layout for each period to minimize the total MHC for all periods and the total rearrangement costs between the periods. Dynamic programming (DP) has been known as one of the effective methods to optimize DFLP. In the DP method, all the possible layouts for every single period are generated and given to DP as its state-space. However, by increasing the number of facilities, it is impossible to give all the possible layouts to DP and only a restricted number of layouts should be fed to DP. This leads to ignoring some layouts and losing the optimality; to deal with this difficulty, an improved DP approach is proposed. It uses a hybrid metaheuristic algorithm to select the initial layouts for DP that lead to the best solution of DP for DFLP. The proposed approach includes two phases. In the first phase, a large set of layouts are generated through a heuristic method. In the second phase, a genetic algorithm (GA) is applied to search for the best subset of layouts to be given to DP. DP, improved by starting with the most promising initial layouts, is applied to find the multi-period layout. Finally, a tabu search algorithm is utilized for further improvement of the solution obtained by improved DP. Computational experiments show that improved DP provides more efficient solutions than DP approaches in the literature. The improved DP can efficiently solve DFLP and find the best layout for each period considering both material handling and layout rearrangement costs. However, rearrangement costs may include some unpredictable costs concerning interruption in production or moving of facilities. Therefore, in some cases, managerial decisions tend to avoid any rearrangements. To this aim, a semi-robust approach is developed to optimize an FLP in a cellular manufacturing system (CMS). In this approach, the pick-up/drop-off (P/D) points of the cells are changed to adapt the layout with changes in product demand and mix. This approach suits more a cellular flexible manufacturing system or a conventional system. A multi-objective nonlinear mixed-integer programming model is proposed to simultaneously search for the optimum number of cells, optimum allocation of facilities to cells, optimum intra- and inter-cellular layout design, and the optimum locations of the P/D points of the cells in each period. A modified non-dominated sorting genetic algorithm (MNSGA-II) enhanced by an improved non-dominated sorting strategy and a modified dynamic crowding distance procedure is used to find Pareto-optimal solutions. The computational experiments are carried out to show the effectiveness of the proposed MNSGA-II against other popular metaheuristic algorithms

Integração da teoria das restrições, manufatura enxuta e seis sigma : análise da aplicação em uma oficina ferroviária

Orientador: Prof. Dr. Marcelo Gechele CletoDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia de Produção. Defesa : Curitiba, 21/02/2018Inclui referências: p.123-129Área de concentração: Tecnologia e InovaçãoResumo: O aumento da produtividade de processos vai além de otimizar o retorno financeiro das empresas, pois está profundamente relacionado ao crescimento da geração de riquezas nos países dessas organizações. Segundo um estudo do Banco Interamericano de Desenvolvimento, os países da américa latina poderiam gerar um PIB 50% maior, se o nível de produtividade de sua população acompanhasse os níveis norte-americanos desde a década de 60. Compreendendo a relevância desse tema, o presente trabalho tem como objetivo avaliar qual é o impacto, sob a perspectiva de produtividade, nos resultados operacionais de uma oficina ferroviária ao se aplicar um modelo de integração da Teoria das Restrições, da Manufatura Enxuta e do Seis Sigma. Por meio de uma pesquisa-ação, foram registrados os detalhes das aplicações das ferramentas propostas no modelo. Ao final do trabalho, os resultados operacionais da oficina melhoraram de forma significativa, o que pode ser verificado nos indicadores de lead time, que foi reduzido em 46%, e de atendimento ao cliente, que antes do projeto possuía uma média de 7,7 locomotivas aguardando peças e, após a aplicação das ferramentas, foi reduzida para 0,7. Foi possível concluir que o modelo de integração forneceu um sequenciamento lógico eficiente para aplicação dos conceitos propostos pelas três abordagens, também foi possível identificar alguns pontos de melhoria no modelo de integração, que poderá ser aplicado em estudos futuros. Palavras Chaves: Teoria das Restrições, Manufatura Enxuta, Seis Sigma, Integração, Ferrovia, Oficina Ferroviária.Abstract: The productivity increase goes beyond the financial returns, it is deeply related to the wealth creation growth in the nations in which they are held. A research made by the Banco Interamericano de Desenvolvimento (BID) states that the Latin America's GDP would be 50% higher if its productivity kept the North American pace since the 1960's. In this scenario, the current work has the goal to evaluate the impact in the productivity process indicators in a railroad repair shop, by the implementation of an integration model of the Theory of Constraints, Lean Manufacturing and Six Sigma. Applying the action research methodology, the tools and concepts application of each approach were registered. At the end, the operational results were improved in a significant way, the lead time was reduced in 46%, the client delivery had reached a higher level, so that, before the integration there was an average of 7,72 locomotives waiting for spare parts and after the project it was reduced to 0,7. The results lead to the conclusion that the integration model had provided a valued logical guide to the efficient application of the tools and concepts of the 3 philosophies, it was also possible to identify some improvements that should be applied to the model in future researches. Key Words: Theory of Constraints, Lean Manufacturing, Six Sigma, Integration Model, Railroad, Repair Shop

Nuevas tecnologías aplicadas a la ergonomía ocupacional. Empleo de sensores RGBD y EyeTracking en la mejora ergonómica de puestos de trabajo

Tesis por compendio[ES] A mediados del siglo XX inició en el continente europeo, especialmente en Francia y Bélgica, una nueva disciplina denominada Ergonomía Centrada en la Actividad. Esta disciplina está enfocada en el análisis del trabajo con el fin de optimizar las condiciones laborales. El propósito de la intervención ergonómica es mejorar componentes que interactúan en el sistema o en la actividad del trabajo (las personas, la organización, la tecnología y el ambiente), interrelacionando aspectos de salud, seguridad, productividad y calidad. En investigaciones anteriores a la presente el doctorando identificó la necesidad de mejora de las herramientas empleadas por los profesionales para la evaluación de factores de riesgo ergonómico, motivando así el desarrollo de la presente investigación. Inicialmente se analizaron métodos generales empleados por los diseñadores para establecer aquellos susceptibles de mejora con la introducción de nuevas tecnologías. En una segunda fase se identificaron y analizaron dispositivos tecnológicos orientados al rastreo de la actividad humana aplicables en el ámbito de las metodologías de la ergonomía ocupacional para los sectores productivos. Como resultado se concluyó que los sensores RGB-D y el Eye-Tracking (rastreo ocular) son dispositivos aplicables para ayudar a mejorar las condiciones en los puestos de trabajo, el primero para distribuir las áreas de trabajo y el segundo para la mejora de las interfaces del usuario. En esta TD se desarrollaron técnicas y métodos para el empleo de estos dispositivos logrando el diseño ergonómico de puestos de trabajo con aplicación práctica (artículos 2 y 3). Durante la realización de esta TD, bajo las directrices del Programa de Doctorado en Tecnologías para la Salud y el Bienestar de la Universidad Politécnica de Valencia, se publicaron tres artículos en revistas que durante el año de su publicación estuvieron indexadas en el primer cuartil de su categoría en el Journal Citation Report, las cuáles sustentan los resultados de la investigación. En ellos se evidenció cómo los avances tecnológicos implementados en Ergonomía producen cambios importantes en el diseño de los puestos de trabajo, y minimizan los tiempos y los movimientos que se requieren en las diferentes actividades laborales, garantizando así una ubicación óptima del recurso humano en los sistemas de producción y generando a su vez estrategias que disminuyen los Trastornos Músculo Esqueléticos (TMEs).[CA] A mitjan segle XX es va desenvolupar en el continent europeu, especialment a França i Bèlgica, una nova disciplina denominada Ergonomia Centrada en l'Activitat. Aquesta disciplina està enfocada en l'anàlisi del treball amb la finalitat d'optimitzar les condicions laborals. El propòsit de la intervenció ergonòmica és millorar els components que interactuen en el sistema o en l'activitat del treball (les persones, l'organització, la tecnologia i l'ambient), interrelacionant els aspectes de salut, seguretat, productivitat i qualitat. En investigacions anteriors a la present el doctorand va identificar la necessitat de millora de les eines emprades pels professionals per a l'avaluació de factors de risc ergonòmic, motivant així el desenvolupament de la present investigació. Inicialment es van analitzar els mètodes habituals empleats pels ergónoms per a establir aquells susceptibles de millora amb la introducció de noves tecnologies. En una segona fase es va identificar i analitzar els dispositius tecnològics orientats al monitoratge de l'activitat humana aplicables en l'àmbit de les metodologies de l'ergonomia ocupacional per als sectors productius. Com a resultat es va concloure que els sensors RGB-D i el Eye-Tracking són dispositius aplicables per a ajudar a millorar les condicions en els llocs de treball, el primer per a distribuir les àrees de treball i el segon per a la millora de les interfícies de l'usuari. En aquesta TD es van desenvolupar tècniques i procediments per a l'ús d'aquests dispositius aconseguint el disseny ergonòmic de llocs de treball amb aplicació pràctica (articles 2 i 3). Durant la realització d'aquesta TD, sota les directrius del Programa de Doctorat en Tecnologies per a la Salut i el Benestar de la Universitat Politècnica de València, es van publicar tres articles en revistes, que durant l'any de la seua publicació, van estar indexades en el primer quartil de la seua categoria en el Journal Citation Report, les quals sustenten els resultats de la investigació. En ells es va evidenciar com els avanços tecnològics implementats en Ergonomia produeixen canvis importants en el disseny dels llocs de treball, minimitzen els temps i els moviments que es requereixen en les diferents activitats laborals, garantint així una ubicació òptima del recurs humà en els sistemes de producció i generant al seu torn estratègies que disminueixen els Trastorns Músculesquelètics.[EN] Around the middle of XX century in Europe, especially in France and Belgium, a new discipline named Activity Focused Ergonomics was developed. This concept is based on the task analysis aiming to optimize working conditions. The purpose of the ergonomic intervention is to improve the components interacting within the system or the work activities (people, organization, technology and environment), correlating all health, safety, productivity and quality facts. In previous research, the ergomists identified the improvement need of those tools used by professionals to assess ergonomic risk factors, enhancing therefore the development of this present research. In the beginning, regular methods used by ergonomics specilists were analized in order to define those that could be improved with the introduction of new technologies. In a second phase, technological devices aimed to monitorize human activity, as well as those applicable for the occupational ergonomics methodologies in productive sectors were identified and analyzed. The conclusion that came as a result was that RGB-D sensors and Eye-Tracking are actual workstations conditions' improving devices, the first one is used to better organize working areas and the second one to optimize the user's interfaces. This Doctoral Thesis develops techniques and procedures to correctly use these devices obtaining workstations ergonomic designs with practical applications (articles 2 and 3). Along the development of this Doctoral Thesis, under the Polytechnic University of Valencia Doctoral School for Health and Wellbeing Technologies program directions, three articles were published in magazines which, throughout their publication year were indexed within its cathegory's first quartile at the Journal Citation Report, supporting the research results. The articles evidenced how the technological progress implemented in Ergonomics produce important changes in the workstations design and minimize times and movements required in different working activities, ensuring human resources' optimal location within the production systems and also developing Musculoskeletal Disorders reduction strategies.Garzón Leal, DC. (2020). Nuevas tecnologías aplicadas a la ergonomía ocupacional. Empleo de sensores RGBD y EyeTracking en la mejora ergonómica de puestos de trabajo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/156052TESISCompendi

Ant colony optimization for solving an industrial layout problem

International audienceThis paper presents ACO_GLS, a hybrid ant colony optimization approach coupled with a guided local search, applied to a layout problem. ACO_GLS is applied to an industrial case, in a train maintenance workshop of the French railway system (SNCF). Results show that an improvement of near 20% is achieved with respect to the actual layout. Since the problem is modeled as a quadratic assignment problem (QAP), we compared our approach with some of the best heuristics available for this problem. Experimental results show that ACO_GLS performs better for small instances, while its performance is still satisfactory for large instances