Short-Term Resource Allocation and Management

Almost all sectors of the economy, such as, government, healthcare, education, ship repair, construction, and manufacturing require project management. A key component of project management deals with scheduling of tasks such that limited resources are utilized in an effective manner. Current research on resource constrained project-scheduling has been classified as: a) Single project with single mode for various tasks, b) Single project with multiple task modes, c) Multiple projects with single task mode, and d) Multiple projects with multiple task modes.;This work extends the current multi-project, multi-mode scheduling techniques. The resources can be renewable, and non-renewable. In addition, it focuses on short term scheduling, that is, scheduling on an hourly, daily, or weekly basis. Long term scheduling assumes a stable system, that is, resources, priorities, and other constraints do no change during the scheduling period. In this research, short term scheduling assumes a dynamic system, that is, resources, priorities, and other constraints change over time.;A hybrid approach is proposed to address the dynamic nature of the problem. It is based on discrete event simulation and a set of empirical rules provided by the project manager. The project manager is assumed to be highly knowledgeable about the project. He/she is regarded as an integral part of the system. Such an approach is better suited to deal with real world scheduling. The proposed approach does not seek to provide a single optimum solution, instead, it generates a series of feasible solutions, along with the impact of each solution on schedule and cost.;Two project case studies dealing with finding an optimum solution were selected from the literature. The proposed technique was applied to the data set in these studies. In both cases the proposed approach found the optimum solution. The model was then applied to two additional problems to test the features that could not be tested on the dataset from the literature.;As for practical implications, the proposed approach enhances the decision making process, by providing more resource allocation flexibility, and results in improved solutions in terms of total project duration and cost. From an academic viewpoint, this research enriches the existing literature, as it provides an extension of the resource constrained project scheduling problems, a discrete event simulation and four cases studies which highlights relevant issues to model properly the complexity of real-life projects

Escalonamento ótimo baseado na teoria de controle supervisório aplicado a um estaleiro de reparo naval

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-graduação em Engenharia de Automação e Sistemas, Florianópolis, 2010A Teoria de Controle Supervisório (TCS) permite a síntese automática de supervisores não bloqueantes que habilitem todas e apenas as sequências que satisfaçam especificações de segurança para um sistema a eventos discretos temporizado. O supervisor ótimo que satisfaz as especificações de recursos, roteiros e prazos para problema do tipo jobshop contém todas as soluções de escalonamento possíveis. No entanto, o crescimento do número de estados dos modelos pode inviabilizar a solução para problemas reais. Nessa pesquisa, uma nova proposta de modelagem dos autômatos temporizados é desenvolvida com o objetivo de reduzir o tamanho dos modelos. Propõe-se também um algoritmo eficiente para síntese de escalonamento baseada na composição incremental dos roteiros de produção e prazos das tarefas e um método de bissecção para minimização do tempo de produção global e também dos tempos de produção de cada tarefa. Este método é aplicado a um estaleiro de reparo naval para o escalonamento das atividades nos cinco recursos principais para execução de dez obras distintas. Também foi desenvolvido um sistema que integra o planejamento da produção com uma ferramenta de síntese automática de supervisores para que o usuário não precise estar familiarizado com a TCS.The Supervisory Control Theory (SCT) allows automatic synthesis of nonblocking supervisors that ensures safety specifications to a timed discrete event system. The optimal supervisory that ensures the resources specifications, production routers, and due dates to the problem of jobshops provides all the possible solutions of scheduling. However, the size of the state space of the models can make impracticable the solution of such a problem. In this dissertation, a new modeling approach is proposed for the timed automata models in order to expressively reduce the size of the models. Also, it is proposed an efficient algorithm for the optimal schedules based on an incremental synthesis of the production routers and due dates. A method of bisection was developed to minimize of total production time and the lead times of jobs as well. This method is applied to a repair shipyard to schedule its activities in the five main resources and ten orders. From the research was developed a system that integrates the production planning with a tool of automatic synthesis of supervisors in order to make the interface an easier place for those users who are not used to SCT