65 research outputs found

    Multicriteria hybrid flow shop scheduling problem: literature review, analysis, and future research

    Get PDF
    This research focuses on the Hybrid Flow Shop production scheduling problem, which is one of the most difficult problems to solve. The literature points to several studies that focus the Hybrid Flow Shop scheduling problem with monocriteria functions. Despite of the fact that, many real world problems involve several objective functions, they can often compete and conflict, leading researchers to concentrate direct their efforts on the development of methods that take consider this variant into consideration. The goal of the study is to review and analyze the methods in order to solve the Hybrid Flow Shop production scheduling problem with multicriteria functions in the literature. The analyses were performed using several papers that have been published over the years, also the parallel machines types, the approach used to develop solution methods, the type of method develop, the objective function, the performance criterion adopted, and the additional constraints considered. The results of the reviewing and analysis of 46 papers showed opportunities for future researchon this topic, including the following: (i) use uniform and dedicated parallel machines, (ii) use exact and metaheuristics approaches, (iv) develop lower and uppers bounds, relations of dominance and different search strategiesto improve the computational time of the exact methods,  (v) develop  other types of metaheuristic, (vi) work with anticipatory setups, and (vii) add constraints faced by the production systems itself

    PHARMACEUTICAL SCHEDULING USING SIMULATED ANNEALING AND STEEPEST DESCENT METHOD

    Get PDF
    In the pharmaceutical manufacturing world, a deadline could be the difference between losing a multimillion-dollar contract or extending it. This, among many other reasons, is why good scheduling methods are vital. This problem report addresses Flexible Flowshop (FF) scheduling using Simulated Annealing (SA) in conjunction with the Steepest Descent heuristic (SD). FF is a generalized version of the flowshop problem, where each product goes through S number of stages, where each stage has M number of machines. As opposed to a normal flowshop problem, all ‘jobs’ do not have to flow in the same sequence from stage to stage. The SA metaheuristic is a global optimization method for solving hard combinatorial optimization problems. SD is a local search method that keeps track only of the current solution and moves only to neighboring permutations based on the largest decrease in the objective function value. The goal of this problem report is to use FF in conjunction with SA to minimize the makespan (length of schedule) in a pharmaceutical manufacturing environment. There are 4 total stages in the tentative production route: granulation, compression, coating, and packaging. This process will be uniform; as in, each stage will have the same number of identical machines. In this study, SA solved the illustrative small-scale example problems precisely and efficiently using a very small amount of computation time. Afterward, the SD heuristic is used to ensure that the best solution found by SA is a local optimum. SD did not improve upon the solutions found by SA

    Secuenciación con Almacenes Limitados. Una Revisión de la Literatura

    Full text link
    [ES] Tradicionalmente, en la aproximación formal a la secuenciación de producción denominada en inglés Theory of Scheduling (o simplemente scheduling), se suele obviar la limitación de capacidad entre los diferentes recursos de cara a establecer el programa de producción. Sin embargo, el paradigma Lean Manufacturing ha dejado patente que la limitación de capacidad física en los sistemas productivos es una característica que influye en los resultados de los programas de producción, por lo que las configuraciones empezando a ser objeto de estudio en la dirección de operaciones. En este artículo se hace una revisión de las principales características de la secuenciación con almacenes limitados que se han abordado bajo la teoría de secuenciación y se resumen las referencias más importantes publicadas durante los últimos años. Finalmente, se presentan una serie de conclusiones con el objetivo de clarificar algunas líneas de interés para los investigadores del tema.Andrés Romano, C.; Maheut, J. (2018). Secuenciación con Almacenes Limitados. Una Revisión de la Literatura. Dirección y organización (Online). 66:17-33. http://hdl.handle.net/10251/145863S17336

    A survey of scheduling problems with setup times or costs

    Get PDF
    Author name used in this publication: C. T. NgAuthor name used in this publication: T. C. E. Cheng2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    Tabu Search: A Comparative Study

    Get PDF

    Production Scheduling in Integrated Steel Manufacturing

    Get PDF
    Steel manufacturing is both energy and capital intensive, and it includes multiple production stages, such as iron-making, steelmaking, and rolling. This dissertation investigates the order schedule coordination problem in a multi-stage manufacturing context. A mixed-integer linear programming model is proposed to generate operational (up to the minute) schedules for the steelmaking and rolling stages simultaneously. The proposed multi-stage scheduling model in integrated steel manufacturing can provide a broader view of the cost impact on the individual stages. It also extends the current order scheduling literature in steel manufacturing from a single-stage focus to the coordinated multi-stage focus. Experiments are introduced to study the impact of problem size (number of order batches), order due time and demand pattern on solution performance. Preliminary results from small data instances are reported. A novel heuristic algorithm, Wind Driven Algorithm (WDO), is explained in detail, and numerical parameter study is presented. Another well-known and effective heuristic approach based on Particle Swarm Optimization (PSO) is used as a benchmark for performance comparison. Both algorithms are implemented to solve the scheduling model. Results show that WDO outperforms PSO for the proposed model on solving large sample data instances. Novel contributions and future research areas are highlighted in the conclusion

    Scheduling and discrete event control of flexible manufacturing systems based on Petri nets

    Get PDF
    A flexible manufacturing system (FMS) is a computerized production system that can simultaneously manufacture multiple types of products using various resources such as robots and multi-purpose machines. The central problems associated with design of flexible manufacturing systems are related to process planning, scheduling, coordination control, and monitoring. Many methods exist for scheduling and control of flexible manufacturing systems, although very few methods have addressed the complexity of whole FMS operations. This thesis presents a Petri net based method for deadlock-free scheduling and discrete event control of flexible manufacturing systems. A significant advantage of Petri net based methods is their powerful modeling capability. Petri nets can explicitly and concisely model the concurrent and asynchronous activities, multi-layer resource sharing, routing flexibility, limited buffers and precedence constraints in FMSs. Petri nets can also provide an explicit way for considering deadlock situations in FMSs, and thus facilitate significantly the design of a deadlock-free scheduling and control system. The contributions of this work are multifold. First, it develops a methodology for discrete event controller synthesis for flexible manufacturing systems in a timed Petri net framework. The resulting Petri nets have the desired qualitative properties of liveness, boundedness (safeness), and reversibility, which imply freedom from deadlock, no capacity overflow, and cyclic behavior, respectively. This precludes the costly mathematical analysis for these properties and reduces on-line computation overhead to avoid deadlocks. The performance and sensitivity of resulting Petri nets, thus corresponding control systems, are evaluated. Second, it introduces a hybrid heuristic search algorithm based on Petri nets for deadlock-free scheduling of flexible manufacturing systems. The issues such as deadlock, routing flexibility, multiple lot size, limited buffer size and material handling (loading/unloading) are explored. Third, it proposes a way to employ fuzzy dispatching rules in a Petri net framework for multi-criterion scheduling. Finally, it shows the effectiveness of the developed methods through several manufacturing system examples compared with benchmark dispatching rules, integer programming and Lagrangian relaxation approaches
    corecore