Minimization of total tardiness in no-wait flowshop production systems with preventive maintenance

Efficient business organizations must balance quality, cost, and time constraints in competitive environments. Reflecting the complexity of this task, we consider manufacturing systems including several stages of production chains requiring time measurement. When production scheduling is not prioritized in such enterprises, several negative effects may occur. A corporation may suffer financial penalties as well as negative brand exposure, and thus may find its credibility challenged. Therefore, in this study, we propose constructive methods to minimize a total tardiness criterion, considering preventative maintenance constraints to reflect the reality of industrial practice, focusing on a no-wait flowshop environment in which jobs are successively processed without operational interruptions. In addition to proposing constructive methods to solve the no-wait flowshop production scheduling problem, a metaheuristic is presented as an approach to improve results obtained by constructive methods. Computational experiments were designed and performed to compare several production scheduling algorithms. Among various constructive heuristics considered, an algorithm called HENLL using an insertion logic showed the best performance. The proposed metaheuristic is based on the iterated greedy (IG) search method, and the results obtained demonstrated significant improvement compared to the heuristics alone. It is expected that this study may be used by production planning and control (PPC) professionals to apply the proposed method to schedule production more efficiently. We show that the proposed method successfully presented a better solution in relation to total tardiness, considering the above mentioned environment

Why Does the Implementation of Quality Management Practices Fail? A Qualitative Study of Barriers in Brazilian Companies

The implementation of Quality Management (QM) practices has been spread after the organizations have realized that such practices could increase competitiveness. Thus, QM is expected to improve customers’ satisfaction and, at the same time, reduce non-quality costs. When these practices are implemented, some organizations obtain positive results, i.e. they improve their competitiveness and productivity, increasing their survival probability and superiority. However, many organizations can not reach their goals. In this context, this paper is the result of a research about the main barriers that cause the failure of the implementation of QM practices. The method of qualitative research was used in two case studies developed in Brazilian manufacturing companies followed by a semi-structured interview with an Operational Management specialist. The main barriers found were lack of support of the company leadership, lack of communication and also plenty of bureaucracy during the implementation. It can be concluded that the main barriers are more related to the elements that support the implementation process, than the inherent characteristics of each QM practice.CNPqFAPESP - Proc 11/12427-31st World Congress of Administrative & Political Sciences (ADPOL-2012

Minimization of total tardiness in flowshop no-wait production system with preventive maintenance

Organizações eficientes são aquelas que conseguem manter equilibradas as vertentes de qualidade, custo e tempo. Em relação ao último, existem várias etapas da cadeia produtiva nas quais o tempo deve ser monitorado. Quando a programação da produção nas indústrias não é priorizado, pode-se incorrer vários efeitos negativos. Um deles, é o atraso em relação à data de entrega, no qual a corporação pode sofrer penalidades financeiras, além de uma exposição negativa para a marca, a qual pode ter sua credibilidade contestada. Dessa forma, essa pesquisa tem por objetivo propor métodos construtivos, que minimize a medida de desempenho total tardiness (atraso total). Para aproximar o método à realidade vivenciada pelas indústrias, será considerada a restrição de manutenção preventiva. Além disso, o ambiente de estudo será o contexto de no-wait flowshop, no qual as tarefas são processados continuamente e sem que haja interrupções entre uma operação e outra de uma mesma tarefa. Além da proposição de métodos construtivos para a resolução do problema, apresenta-se uma metaheurística como forma de demostrar como pode-se aprimorar os resultados gerado pelos métodos construtivos. Experimentações computacionais foram elaboradas e realizadas para comparação dos algoritmos. Dentre as heurísticas construtivas a que apresentou melhor desempenho foi a \"EDD + NEH + LS1 + LS2\'\', na qual utiliza uma lógica de inserção. A metaheurística proposta é baseada no procedimento IG (iterated greedy), sendo que há melhora de resultado em relação as heurísticas construtivas. Assim, espera-se que essa pesquisa possa ser utilizada e aplicada pela indústria de manufatura para aumentar a efetividade da programação da produção.Efficient organizations are those that manage to keep the quality, cost and time strands balanced. With respect to the variable time, there are several stages of the production chain in which it must be monitored. When scheduling in companies is not prioritized, several negative effects incur. One of them is the delay in relation to the due date, for which the corporation can suffer financial penalties, in addition to a negative exposure to the brand, which may have its credibility challenged. Therefore, this research aims to propose constructive methods, which minimizes the performance criterion of total tardiness. In order to approximate the method to the reality of the industries, preventive maintenance constraints will be considered. And the environment of the study will be the no-wait flowshop, in which jobs are processed continuously and without interruptions between one operation and another of the same job. In addition to proposing constructive methods to solve the problem, a metaheuristic is presented as a way of demonstrating how to improve the results generated by the constructive methods. Computational experiments were elaborated and performed for comparison of the algorithms. Among the constructive heuristics that presented the best performance was \"EDD + NEH + LS1 + LS2\", in which it uses an insertion logic. The proposed metaheuristic is based on the IG (iterated greedy) procedure, and there is an improvement of the result in relation to the constructive heuristics. Thus, it is expected that this research can be used and applied by the manufacturing industry to increase the effectiveness of scheduling