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1
Content available Method of rescheduling for hybrid production lines with intermediate buffers
Magiera Marek
Archives of Control Sciences
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2020
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Vol. 30, No. 2
213--231
EN
A method of creating production schedules regarding production lines with parallel machines is presented. The production line setup provides for intermediate buffers located between individual stages. The method mostly concerns situations when part of the production machines is unavailable for performance of operations and it becomes necessary to modify the original schedule, the consequence of which is the need to build a new schedule. The cost criterion was taken into account, as the schedule is created with the lowest possible costs regarding untimely completion of products (e.g. fines for delayed product completion). The proposed method is relaxing heuristics, thanks to which scheduling is performed in a relatively short time. This was confirmed by the presented results of computational experiments. These experiments were carried out for the rescheduling of machine parts production.
2
Content available Algorithms Using List Scheduling and Greedy Strategies for Scheduling in the Flowshop with Resource Constraints
Figielska E.
Zeszyty Naukowe Warszawskiej Wyższej Szkoły Informatyki
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2014
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nr 11
29--39
EN
The paper addresses the problem of scheduling in the two-stage flowshop with parallel unrelated machines and renewable resource constraints. The objective is minimization of makespan. The problem is NP-hard. Fast heuristic algorithms using list scheduling and greedy strategies are proposed. For evaluation of the performance of the algorithms computational experiments are performed on randomly generated test problems, and results are reported.
3
Content available A relaxation heuristic for scheduling flowshops with intermediate buffers
Magiera M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2013
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Vol. 61, nr 4
929--942
EN
The paper presents a two-level relaxation heuristic for production planning for multistage flowshop systems with intermediate buffers. The method concerns unidirectional multistage systems where tasks with respect to many various types of products are performed simultaneously. The fixed and the alternative production routes are regarded in the method. The top-level is a stage loading, i.e., allocation of tasks among the stages. The base-level is a task scheduling - allocation of tasks among the stations. The linear mathematical models of mixed integer programming are used in the method. The time criterion is used in the minimization functions - the minimal schedule is fixed. The condition that variables are to be integers has been ignored in the heuristic. The relaxed heuristic developed in such a manner enables obtaining good results in a very short time. This paper discusses the multilevel approach as the developed production scheduling method serves the purpose of solving relatively large problems. Results of computational experiments with the proposed heuristic method are presented.
4
Content available Effective Design of the Simulated Annealing Algorithm for the Flowshop Problem with Minimum Makespan Criterion
Hurkała J., Hurkała A.
Journal of Telecommunications and Information Technology
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2012
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nr 2
92-98
EN
In this paper we address the n-job, m-machine flowshop scheduling problem with minimum completion time (makespan) as the performance criterion. We describe an efficient design of the Simulated Annealing algorithm for solving approximately this NP-hard problem. The main difficulty in implementing the algorithm is no apparent analogy for the temperature as a parameter in the flowshop combinatorial problem. Moreover, the quality of solutions is dependent on the choice of cooling scheme, initial temperature, number of iterations, and the temperature decrease rate at each step as the annealing proceeds. We propose how to choose the values of all the aforementioned parameters, as well as the Boltzmann factor for the Metropolis scheme. Three perturbation techniques are tested and their impact on the solutions quality is analyzed. We also compare a heuristic and randomly generated solutions as initial seeds to the annealing optimization process. Computational experiments indicate that the proposed design provides very good results - the quality of solutions of the Simulated Annealing algorithm is favorably compared with two different heuristics.
5
Content available remote Minimizing total tardiness in no-wait flowshops
Aldowaisan T., Allahverdi A.
Foundations of Computing and Decision Sciences
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2012
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Vol. 37, No. 3
149--162
EN
We address the m-machine no-wait flowshop scheduling problem where the objective is to minimize total tardiness. To the best of our knowledge, the considered problem has not been addressed so far. We propose heuristic solutions since the problem is NP-hard. Initially, we consider a number of dispatching rules commonly used for the considered objective in other scheduling environments. We identify through computational experiments the best performing dispatching rule and then propose simulated annealing (SA) and genetic algorithms (GA) by using the best performing dispatching rule as an initial solution. This achieves at least 50% improvement in the SA and GA performances. Next, we propose enhanced versions of SA and GA and show through computational experiments that the enhanced versions provide over 90% further improvement. The performance of enhanced GA is slightly better than that of enhanced SA however, the computation time of enhanced GA is about 10 times that of enhanced SA. Therefore, we conclude that the enhanced SA outperforms the enhanced GA.
6
Content available Linear programming & metaheuristic approach for scheduling in the hybrid flowshop with resource constraints
Figielska E.
Control and Cybernetics
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2011
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Vol. 40, no 4
1209-1230
EN
This paper deals with the problem of preemptive scheduling in a two-stage flowshop with parallel unrelated machines and additional renewable resources. The objective is the minimization of makespan. The problem is NP-hard. Heuristic algorithms are proposed which join the linear programming based procedures with metaheuristic algorithms: genetic, simulated annealing and tabu search algorithm. The performance of the proposed algorithms is experimentally evaluated by comparing the solutions with a lower bound on the optimal makespan. Results of a computational experiment show that these algorithms are able to produce good solutions in short computation time and that the metaheuristics significantly improve the results for the most difficult problems.
7
Content available remote Heuristic algorithms for preemptive scheduling in a Two-stage flowshop with unrelated parallel machines and 0-1 resource requirements
Figielska E.
Control and Cybernetics
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2009
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Vol. 38, no 3
723-743
EN
The paper considers the problem of preemptive scheduling in a two-stage flowshop with parallel unrelated machines at the first stage and a single machine at the second stage. At the first stage, jobs use some additional renewable resources which are available in limited quantities. The resource requirements are of 0-1 type. The objective is minimization of the makespan. The problem is NP-hard. We develop heuristic algorithms which first solve the problem occurring at stage 1, and then find a final schedule in the flowshop. An extensive computational experiment shows that the proposed heuristic algorithms can be an efficient tool capable of finding good quality solutions.
8
Content available remote Monolityczna metoda selekcji i szeregowania sekwencji montażowych dla systemów przepływowych.
Magiera M.
Technologia i Automatyzacja Montażu
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2007
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nr 2-3
10-13
9
Content available Three-machine flowshop scheduling problem to minimize total completion time with bounded setup and processing times
Allahverdi A.
Decision Making in Manufacturing and Services
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2007
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Vol. 1, no. 1-2
5-23
EN
The three-machine flowshop scheduling problem to minimize total completion time is studied where setup times are treated as separate from processing times. Setup and processing times of all jobs on all machines are unknown variables before the actual occurrence of these times. The lower and upper bounds for setup and processing times of each job on each machine is the only information that is available. In such a scheduling environment, there may not exist a unique schedule that remains optimal for all possible realizations of setup and processing times. Therefore, it is desired to obtain a set of dominating schedules (which dominate all other schedules) if possible. The objective for such a scheduling environment is to reduce the size of dominating schedule set. We obtain global and local dominance relations for a three-machine flowshop scheduling problem. Furthermore, we illustrate the use of dominance relations by numerical examples and conduct computational experiments on randomly generated problems to measure the effectiveness of the developed dominance relations. The computational experiments show that the developed dominance relations are quite helpful in reducing the size of dominating schedules.
10
Content available remote Algorytmy selekcji sekwencji montażowych dla systemów przepływowych z uzględnieniem przestojów maszyn.
Magiera M.
Technologia i Automatyzacja Montażu
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2006
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nr 2
30-33
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