Baskar P

Department of Automotive Engineering

School of Mechanical Engineering

Vellore Campus

Anthony Xavior M

Department of Manufacturing Engineering

Dhanasakkaravarthi B.

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Indian Journal of Science and Technology

A permutation flow shop scheduling problem involves the determination of the order of processing the required number of jobs having different processing times over different machines with an objective of minimising a performance parameter. For makespan minimisation, the problem is NP-complete and many heuristics have been developed over the years. It is generally accepted that the heuristic developed by Nawaz, Enscore and Ham (NEH heuristic) is the most efficient so far among the simple heuristics. NEH algorithm sorts the jobs in descending order of their total processing times. Initial sequence is constructed by selecting the first two jobs and other jobs are inserted one by one to obtain the makespan and the corresponding sequence. This paper analyses the powerful job insertion technique of NEH algorithm using different combinations of the total processing time and total machine idle time for different initial sequences. Taillard benchmark problems are used for the analysis.

International Journal of Enterprise Network Management

Analysis of job insertion technique for different initial sequences in permutation flow shop scheduling problems

Finding an optimal sequence in terms of total completion time for processing 'n' jobs in 'm' processing centres in the shop floor is an important job for a shop floor supervisor. The problem is NP hard as the total number of sequences is (n!) for a permutation flow shop scheduling problem. After the invention of evolutionary algorithms and meta heuristics, finding an optimal sequence becomes comparatively easier. However, in the shop floor, due to the limitation in the computing capabilities and computer knowledge, still the classical heuristics are popular because of their simplicity. However, in most of the cases, only one sequence is obtained except in CDS algorithm where the best sequence is selected from (m-1) alternatives. This paper deals with finding more than one sequence having optimal/near optimal make span in a permutation flow shop scheduling problem using the concept of dummy machine. The concept is used with some of the classical heuristics like CDS, Palmer slope index method, RA method. The effect of dummy machine is analysed using the well known Taillard bench mark problems. The codes are generated in MATLAB and the results are satisfactory. Â© 2012 Inderscience Enterprises Ltd.

International Journal of Materials and Product Technology

Effects of dummy machines on make span in a few classical heuristics using Taillard bench mark problems

Comparison of Genetic Algorithm with Particle Swarm Optimisation, Ant Colony Optimisation and Tabu Search based on University Course Scheduling System

Two Stage Flow Shop Scheduling under Fuzzy Environment

Computers & Operations Research

On insertion tie-breaking rules in heuristics for the permutation flowshop scheduling problem

Impact of Initial Partial Sequence in the Makespan, in Permutation Flow Shop Scheduling Heuristic Algorithms – An Analysis

Journal	Indian Journal of Science and Technology
Publisher	Indian Society for Education and Environment
ISSN	0974-6846
Open Access	Yes