7,273 research outputs found
Design and Analysis of an Estimation of Distribution Approximation Algorithm for Single Machine Scheduling in Uncertain Environments
In the current work we introduce a novel estimation of distribution algorithm
to tackle a hard combinatorial optimization problem, namely the single-machine
scheduling problem, with uncertain delivery times. The majority of the existing
research coping with optimization problems in uncertain environment aims at
finding a single sufficiently robust solution so that random noise and
unpredictable circumstances would have the least possible detrimental effect on
the quality of the solution. The measures of robustness are usually based on
various kinds of empirically designed averaging techniques. In contrast to the
previous work, our algorithm aims at finding a collection of robust schedules
that allow for a more informative decision making. The notion of robustness is
measured quantitatively in terms of the classical mathematical notion of a norm
on a vector space. We provide a theoretical insight into the relationship
between the properties of the probability distribution over the uncertain
delivery times and the robustness quality of the schedules produced by the
algorithm after a polynomial runtime in terms of approximation ratios
A Hybrid Bacterial Swarming Methodology for Job Shop Scheduling Environment
Optimized utilization of resources is the need of the hour in any manufacturing system. A properly planned schedule is often required to facilitate optimization. This makes scheduling a significant phase in any manufacturing scenario. The Job Shop Scheduling Problem is an operation sequencing problem on multiple machines with some operation and machine precedence constraints, aimed to find the best sequence of operations on each machine in order to optimize a set of objectives. Bacterial Foraging algorithm is a relatively new biologically inspired optimization technique proposed based on the foraging behaviour of E.coli bacteria. Harmony Search is a phenomenon mimicking algorithm devised by the improvisation process of musicians. In this research paper, Harmony Search is hybridized with bacterial foraging to improve its scheduling strategies. A proposed Harmony Bacterial Swarming Algorithm is developed and tested with benchmark Job Shop instances. Computational results have clearly shown the competence of our method in obtaining the best schedule
Recommended from our members
Bicriteria scheduling of a two-machine flowshop with sequence-dependent setup times
The official published version of the article can be found at the link below.A two-machine flowshop scheduling problem is addressed to minimize setups and makespan where each job is characterized by a pair of attributes that entail setups on each machine. The setup times are sequence-dependent on both machines. It is shown that these objectives conflict, so the Pareto optimization approach is considered. The scheduling problems considering either of these objectives are NP-hard , so exact optimization techniques are impractical for large-sized problems. We propose two multi-objective metaheurisctics based on genetic algorithms (MOGA) and simulated annealing (MOSA) to find approximations of Pareto-optimal sets. The performances of these approaches are compared with lower bounds for small problems. In larger problems, performance of the proposed algorithms are compared with each other. Experimentations revealed that both algorithms perform very similar on small problems. Moreover, it was observed that MOGA outperforms MOSA in terms of the quality of solutions on larger problems.Partial Funding from EPSRC under grant EP/D050863/1
Particle swarm optimization applied to job shop scheduling
In this project we have to apply the particle swarm optimization algorithm to job shop scheduling problem. Job shop scheduling is a combinatorial optimization problem where we have to arrange the jobs which may or may not be processed in every machine in a particular sequence and each machine has a different sequence of jobs. Job shop scheduling is a complex extended version of flow shop scheduling which is a problem where each job is processed through each and every machine and each machine has a same sequence of jobs. Our main objective in both kind of problem is to arrange the jobs in a sequence which gives minimum value of make span. PSO (Particle swarm optimization) helps us to find a combination of job sequence which has the least make span. In PSO a swarm of particles which have definite position and velocity for each job. In PSO, to find the combinations we use a heuristic rule called Smallest Position Value (SPV). According to smallest position value rule jobs are arranged in ascending order of their positions i.e. job having least position value is put first in sequence. In this project PSO is first applied to flow shop scheduling problem. This is done to understand how PSO algorithm can be applied to scheduling problem as flow shop scheduling problem is a simple problem. After Understanding the PSO algorithm, the algorithm is extended to apply in job shop scheduling problem for n jobs and m machines
Local search Methods to Solve The Sum of Two Objective Functions
In this paper, the problem of sequencing a set of n jobs on single machine was considered to minimize theobjective function. The aim is to find the optimal or near optimal solution (scheduling) for the objective function consists of a sum of total late work and maximum lateness. This problem is strongly NP-hard. Simulated Annealing, Ant colony Algorithm, and usagea hybridization as a tool to solved the problem approximatelywith up to 100000 jobs in a reasonable time 10 minutes
Optimizing the performance of an integrated process planning and scheduling problem: an AIS-FLC based approach
The present market scenario demands an integration of process planning and scheduling to stay competitive with others. In the present work, an integrated process planning and scheduling model encapsulating the salient features of outsourcing strategy has been proposed. The paper emphasizes on the role of outsourcing strategy in optimizing the performance of enterprises in rapidly changing environment. In the present work authors have proposed an artificial immune system based AIS-FLC algorithm embedded with the fuzzy logic controller to solve the complex problem prevailing under such scenario, while simultaneously optimizing the performance. The authors have shown the efficacy of the proposed algorithm by comparing the results with other random search methods
An enhanced ant colony optimization approach for integrated process planning and scheduling
An enhanced ant colony optimization (eACO) meta-heuristics is proposed in this paper to accomplish the integrated process planning and scheduling (IPPS) in the jobshop environments. The IPPS problem is graphically formulated to implement the ACO algorithm. In accordance with the characteristics of the IPPS problem, the mechanism of eACO has been enhanced with several modifications, including quantification of convergence level, introduction of pheromone on nodes, new strategy of determining heuristic desirability and directive pheromone deposit strategy. Experiments are conducted to evaluate the approach, while makespan and CPU time are used as measurements. Encouraging results can be seen when comparing to other IPPS approaches based on evolutionary algorithms. © 2013 International Institute for Innovation, Industrial Engineering and Entrepreneurship - I4e2.published_or_final_versio
- …