A PTAS for Minimizing Weighted Completion Time on Uniformly Related Machines (Extended Abstract)
Files
Penn collection
Degree type
Discipline
Subject
average completion time
scheduling
uniformly related machines
weighted completion time
Funder
Grant number
License
Copyright date
Distributor
Related resources
Author
Contributor
Abstract
We consider the well known problem of scheduling jobs with release dates to minimize their average weighted completion time. When multiple machines are available, the machine environment may range from identical machines (the processing time required by a job is invariant across the machines) at one end of the spectrum to unrelated machines (the processing time required by a job on each machine is specified by an arbitrary vector) at the other end. While the problem is strongly NP-hard even in the case of a single machine, constant factor approximation algorithms are known for even the most general machine environment of unrelated machines. Recently a PTAS was discovered for the case of identical parallel machines [1]. In contrast, the problem is MAX SNP-hard for unrelated machines [11]. An important open problem was to determine the approximability of the intermediate case of uniformly related machines where each machine has a speed and it takes p/s time to process a job of size p on a machine with speed s. We resolve the complexity of this problem by obtaining a PTAS. This improves the earlier known approximation ratio of (2 + ε).
Advisor
Date of presentation
Conference name
Conference dates
Conference location
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Volume number
Issue number
Publisher
Publisher DOI
Comments
Postprint version. Published in Lecture Notes in Computer Science, Volume 2076, Automata, Languages, and Programming, 2001, pages 848-861. Publisher URL: http://springerlink.metapress.com/link.asp?id=105633