An expert system to minimize operational costs in mixed-model sequencing problems with activity factor

One of the major issues in industrial environments is currently maximizing productivity while reducing manufacturing cost. This can be seen clearly reflected in mixed-model assembly lines based systems, where obtaining efficient manufacturing sequences is a key to be competitive in a dynamic and globalized market. However, this continuous cost reduction and productivity growth should not penalize the welfare of employees. This work is intended to address this lack of compatibility between the economic and social objectives through the study of the mixed-model sequencing problem from both the business and labor perspective. This is done by considering the possibility of reducing or increasing processing times of operations by varying the work pace of line's operators within the permissible legal boundaries. Thus, depending on this flexible activation time of operators, the amount of completed work and idle time will be one or the other and, consequently, the productivity of the line will also improve or get worse. In this regard, we propose new approach to the sequencing problem without incurring cost increases and providing a safe working environment, in accordance with applicable law. This new approach leads to obtain efficient manufacturing sequences, in terms of both productivity and labor conditions. Specifically, the objective of the new problem is minimizing the unproductive costs of the line by incorporating the possibility of increasing production through the variation of the work pace of line's operators. Increasing the work pace of operators, the amount of non-completed work or the preventable idle time can be reduced and therefore, their associated costs too. In addition, and without losing sight of the effort involved in working with a work pace above the normal, we propose several economic criteria to compensate the activation of workers where necessaryPeer ReviewedPostprint (author's final draft

Análise de problemas de transporte sob a perspectiva da teoria de jogos

Orientadores: Flávio Keidi Miyazawa, Rafael Crivellari Saliba SchoueryDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Problemas relacionados com meios de transporte são comumente encontrados na área de Otimização Combinatória, como, por exemplo, o Problema do Caixeiro Viajante e o Problema de Roteamento de Veículos. Nesta dissertação, consideramos um problema de transporte sob a perspectiva da teoria de jogos algorítmica onde todos os jogadores querem ser transportados a um destino em comum o mais rápido possível, e para isso eles devem escolher um dentre os ônibus disponíveis. Revisamos alguns resultados quanto à existência e à ineficiência de equilíbrios puros de Nash em relação a duas funções sociais. Então, apresentamos limitantes para o Preço de Anarquia para uma nova função social, chamada de função utilitária. Consideramos também o jogo na forma extensiva, o qual chamamos de jogos de transporte sequenciais e apresentamos limitantes para o Preço da Anarquia Sequencial considerando três funções sociais, para instâncias métricas e não-métricasAbstract: Problems related to transportation, such as the Traveling Salesman Problem and the Vehicle Routing Problem, commonly appear in the Combinatorial Optimization area. In this master¿s thesis, we present a game-theoretic analysis of a transportation game where all players want to be transported to a common destination as quickly as possible and, in order to achieve this goal, they have to choose one of the available buses. We review some results concerned with the existence and inefficiency of Pure Nash Equilibria in relation with two social functions. Then, we give bounds on the Price of Anarchy to a new social function, called the utilitarian function. Furthermore, we consider the game in its extensive form, which we call sequential transportation games, and then we provide bounds for the Sequential Price of Anarchy considering three social functions in both metric and non-metric instancesMestradoCiência da ComputaçãoMestre em Ciência da Computação2017/05223-9148027/2016-4FAPESPCNP