scholarly journals Memetic algorithm used in a flow shop scheduling problem

Author(s):  
Jorge Armando Ramos-Frutos ◽  
Didia Carrillo-Hernández ◽  
Alan David Blanco-Miranda ◽  
Heraclio García-Cervantes

Scheduling activities in flow shops involves generating a sequence in which the jobs must be processed. To generate the sequence, some criteria are taken into account, such as the completion time of all the jobs, delay time in delivery, idle time, cost of processing the jobs, work in process, among others. In this case, completion time of all jobs and idle time are taken as the objective function. To generate the sequence, a Memetic Algorithm (MA) is used that combines Simulated Annealing (SA) and Genetic Algorithms (GA) to solve the problem. A permutation type decoding was used for the vectors that make up the MA population. The SA was used for the generation of the initial population. Selection, recombination and mutation processes are generated in a similar way to GA. In this case there are 6 parameters to be set; temperature, z parameter, recombination probability, mutation probability, cycles and initial population. To set these parameters, the Response Surface Methodology is used for two objectives. Achieving improvements in the algorithm result of at least 2%. These results help to minimize processing times which impacts with the economics of the enterprise. Using the MA in an interface that helps the user to make a decisión about the Schedule of the Jobs.

Author(s):  
PENG-JEN LAI ◽  
HSIEN-CHUNG WU

The flow shop scheduling problems with fuzzy processing times are investigated in this paper. For some special kinds of fuzzy numbers, the analytic formulas of the fuzzy compltion time can be obtained. For the general bell-shaped fuzzy numbers, we present a computational procedure to obtain the approximated membership function of the fuzzy completion time. We define a defuzzification function to rank the fuzzy numbers. Under this ranking concept among fuzzy numbers, we plan to minimize the fuzzy makespan and total weighted fuzzy completion time. Because the ant colony algorithm has been successfully used to solve the scheduling problems with real-valued processing times, we shall also apply the ant colony algorithm to search for the best schedules when the processing times are assumed as fuzzy numbers. Numerical examples are also provided and solved by using the commercial software MATLAB.


2013 ◽  
Vol 651 ◽  
pp. 548-552
Author(s):  
Parinya Kaweegitbundit

This paper considers two stage hybrid flow shop (HFS) with identical parallel machine. The objectives is to determine makespan have been minimized. This paper presented memetic algorithm procedure to solve two stage HFS problems. To evaluated performance of propose method, the results have been compared with two meta-heuristic, genetic algorithm, simulated annealing. The experimental results show that propose method is more effective and efficient than genetic algorithm and simulated annealing to solve two stage HFS scheduling problems.


The present paper deals with a problem of n*2 flow shop scheduling where setup time of the machines are separated from their dispensation time and transportation time for moving from first machine to second machine is also given. Our aim is to get the most favorable jobs sequence which can make machines idle time equal to zero so that rental cost can be minimized. In order to ensure no idle constraint, we have developed an algorithm in which we have delayed the start time of machine B, so that machine B works continuously without any idle time. A simple mathematical example is also given to clear the concept.


OR Spectrum ◽  
2018 ◽  
Vol 40 (3) ◽  
pp. 809-829 ◽  
Author(s):  
Matthias Bultmann ◽  
Sigrid Knust ◽  
Stefan Waldherr

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