29 research outputs found

    Use of Excel worksheets with user-friendly interface in batch process (PSBP) to minimize the makespan

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    In the chemical industry, the necessity for scheduling is becoming more pronounced, especially in batch production mode. Nowadays, planning industrial activities is a necessity for survival. Intense competition requires diversified products and delivery in accordance with the requirements of consumers. These activities require quick decision making and the lowest possible cost, through an efficient Production Scheduling. So, this work addresses the Permutation Flow Shop scheduling problem, characterized as Production Scheduling in Batch Process (PSBP), with the objective of minimizing the total time to complete the schedule (Makespan). A method to approach the problem of production scheduling is to turn it into Mixed Integer Linear Programming- MILP, and to solve it using commercial mathematical programming packages. In this study an electronic spreadsheet with user-friendly interface (ESUFI) was developed in Microsoft Excel. The ease of manipulation of the ESUFI is quite evident, as with the use of VBA language a user-friendly interface could be created between the user and the spreadsheet itself. The results showed that it is possible to use the ESUFI for small problems

    A Branch-and-Bound Algorithm for Minimizing the Energy Consumption in the PFS Problem

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    This paper considers the energy consumption minimization in permutation flow shop (PFS) scheduling problem. The energy consumption of each machine is decomposed into two parts: useful part which completes the operation at current stage and wasted part which is consumed during idle period. The objective considered here is to minimize the total wasted energy consumption which is a weighted summation of the idle time of each machine. To solve this new problem, a branch-and-bound algorithm is developed. Two lower bounds are proposed, and an initial upper bound by using a variant of NEH heuristic algorithm is applied. Compared with the makespan minimization criterion, this model deduces more energy-saving solutions. Experimental results also validate the efficiency of the proposed algorithm for problems with job number not larger than 15

    An adaptive branching rule for the permutation flow-shop problem : (preprint)

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    An ant colony system for solving fuzzy flow shop scheduling problem

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    Benchmarking Permutation Flow Shop Problem: Adaptive and Enumerative Approaches Implementations via Novel Threading Techniques

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    A large number of real-world planning problems are combinatorial optimization problems which are easy to state and have a finite but usually very large number of feasible solutions. The minimum spanning tree problem and the shortest path problem are some which are solvable through polynomial algorithms. Even though there are other problems such as crew scheduling, vehicle routing, production planning, and hotel room operations which have no properties such as to solve the problem with polynomial algorithms. All these problems are NP-hard. The permutation flow shop problem is also NP-hard problem and they require high computation. These problems are solvable as in the form of the optimal and near-optimal solution. Some approach to get optimal are exhaustive search and branch and bound whereas near optimal are achieved annealing, Genetic algorithm, and other various methods. We here have used different approach exhaustive search, branch and bound and genetic algorithm. We optimize these algorithms to get performance in time as well as get the result closer to optimal. The exhaustive search and branch and bound gives all possible optimal solutions. We here have shown the comparative result of optimal calculation for 10 jobs with varying machine number up to 20. The genetic algorithm scales up and gives results to the instances with a larger number of jobs and machines

    On tie-breakers and other exotic Tools for the NEH Algorithm

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    Este es el primero de tres trabajos dedicados a procedimientos de resolución de los problemas flowshop con criterio minimización del makespan, basados en la clásica heurística de Nawaz, Enscore y Ham. Consideramos dos casos el Fm|prmu|Cmax y el Fm|block|Cmax. En el presente trabajo analizamos los procedimientos de desempate en la intercalación del segundo paso del NEH. Basamos las conclusiones en los experimentos realizados tomando como base los 120 ejemplares de las colecciones de Taillard. Son suficientemente conocidos y ejercen cierta fascinación sobre los investigadores. En el anexo recogemos resultados sobre otras colecciones, más numerosas, generadas siguiendo los principios establecidos por Taillard.Preprin

    Note on the blocking flow shop problem

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    We present some results attained with different algorithms for the Fm|block|Cmax problem using as experimental data the well-known Taillard instances

    New insights on the blocking flow shop problem

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    We present some results attained with different algorithms for the Fm|block|Cmax problem using as experimental data the well-known Taillard instances.Preprin

    An investigation of transitional management problems for the NSTS at NASA

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    This quarterly report summarizes the ideas and concepts developed by the University of Houston team with the collaboration and support of the Management Integration Offices of NASA. In addition it is hoped that this report will help to stimulate the healthy problem solving process already present at NASA. This is the second report in the fourth year of the research contract. The main aim of the work is to assist the National Space Transportation System (NSTS) in finding ways and means of moving into a truly operational era in the sense of routine timely production of flights. The reader who seeks an understanding of the concepts presented is encouraged to read the reports of the last three years. The overall strategy of this effort is to: (1) search the literature for applications of transition management and other related issues, (2) conduct investigations into the experiences of the industries with the transition management, and (3) to adapt the information found in (1) and (2) above into a form useful to NASA while at the same time applying industrial engineering and engineering management expertise to problems and issues as they emerge
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