Case Study On Job Shop Scheduling

1902 Words 8 Pages
CHAPTER1
INTRODUCTION

1.1 Introductory Remarks
In this chapter, the scheduling problems, their concept and theirdifferent types are briefly covered.A brief introduction to the role of schedulingis given.Description of JobShop Scheduling Problem (JSSP)is presented with its practical complication.Types of schedulingand objectives of the study are summarized. Also, A brief introduction about the plan of the project is given.Research layout at the end of the chapter is presented.
1.2Scheduling Problems
One of the most necessary and vital subject in planning and managingmanufacturing system is operations scheduling. Scheduling is the process of allocatingresources, (i.e. machines, people and others) over time to competitive activities (jobs,
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In a easier version of this problem, flow shop scheduling[1,10], it is generally assumed that all jobs must be processed on all machines in the same machine order. A more complex case is represented by job shop scheduling; the jobs may be processed following different machine orders. There is no common path of movement of jobs from machine to machine. As mentioned by Zandieh et al [11], (Nowickiand Smatnicki,1996) and (Jain and Meeran, 1999), defined the JobShop Scheduling Problem (JSSP) by, is one of the hardest combinatorial optimization problems, as it is classified as NP-Hard problem andtherefore no deterministic algorithms can solve them in a reasonable amount of time. Job shop scheduling problem aims to find suitable sequencing of jobs on machines to optimize the performance …show more content…
However, most scheduling researchesare limited to a single objective, which is the optimization of makespan (the maximum completion time of all jobs). However, real-life scheduling problems often require a decision maker who considers a number of criteria before taking a decision. A solution that may appear optimal with respect to one given criterion may becomea poor candidate for some other criteria, like mean flow-time, total tardiness,and others. Therefore, the trade-offs involved in considering several different criteria provide useful insights for decision makers

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