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Optimization of multi objective Job Shop Scheduling problems using
Firefly algorithm
K.C.Udaiyakumar 1a* , M.Chandrasekaran 2
1Research Scholar, Sathyabama University, Chennai, India.
2Director, Department of Mechanical Engineering,Vels University, Chennai, India
akcudaiyakumar1967@gmail.com
Key words: Job shop scheduling problem, fire-fly, make span, mean flow time, tardiness,
benchmark.
Abstract. Scheduling is the allocation of resources over time to carry out a collection of tasks
assigned in any field of engineering and non engineering. Majority of JSSP are categorized into non
deterministic (NP) hard problem because of its complexity. Scheduling are generally solved by
using heuristics to obtain optimal or near optimal solutions because problems found in practical
applications cannot be solved to optimality using available resources in many cases. Many
researchers attempted to solve the problem by applying various optimization techniques. While
using traditional methods they observed huge difficulty in solving high complex problems and
meta-heuristic algorithms were proved most efficient algorithms to solve various JSSP so far. The
objective of this paper i) to make use of a newly developed meta heuristic called Firefly algorithm
(FA) because of inspiration on Firefly and its characteristic. ii) To find the combined objective
function by determining optimal make span, mean flow time and tardiness of different size
problems (using Lawrence 1-40 problems) as a bench marking dataset and to find the actual
computational time. iii) The analysis of the experimental results on Firefly algorithm based on
computational time is compared with other algorithms.
Introduction.
Job shop scheduling problem is one of the most difficult combinatorial problems. Scheduling is the
allocation of resources over time to perform a collection of tasks.The job shop scheduling
problem(JSP) consists of a set of m machines {M1,M2,........Mm}, and a collection of n jobs
{J1,J2.....Jn} to be scheduled, where each job must pass through each machine once only.
Each job has its own processing order and this may bear no relation to the processing order
of the any other job. Job Shop Scheduling problems are NP-hard problem, so its complexity is
more. Various optimization approaches have been widely applied to solve the JSSP. Conventional
methods based on mathematical methods and /or full numerical search (for example, Branch
and Bound [3,4] and Lagrangian Relaxation [5,6]) can guarantee the optimal solution. They
have been successfully used to solve the JSSP. However, these methods highly consume
computational time and resources even for solving moderately-large problem size and therefore
impractical if the computational limitation exists. Later, a larger size JSSP has been solved by an
approximation methods metaoroptimization -heuristics as such searchTabu [6], simulated
annealing [7], and nature inspired algorithms such as PSO[10]. The objective of this paper is i) to
make use of a recently developed meta heuristic called Firefly algorithm (FA) because of
inspiration on Firefly and its characteristic. ii) to find the combined objective function on,multi
objectives of JSSP[11,12] (i.e. make span minimization, tardiness and mean flow time) using 1-40
Lawrance problems[8,9,13]and iii) The analysis of the experimental results( computational time)
on Firefly algorithm is compared with HGA[14].
Firefly algorithm.
Inspiration and algorithm. Firefly algorithm idealizes some of the characteristics of the firefly
behavior. They follow three rules: a) all the fireflies are unisex, b) each firefly is attracted only
to the fireflies ,that are brighter than itself; Strength of the attractiveness is proportional to
Applied Mechanics and Materials Submitted: 2014-05-08
ISSN: 1662-7482, Vol. 591, pp 157-162 Revised: 2014-05-23
doi:10.4028/www.scientific.net/AMM.591.157 Accepted: 2014-05-23
© 2014 Trans Tech Publications Ltd, All Rights Reserved Online: 2014-07-18
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