Title
On truthfulness and approximation for scheduling selfish tasks
Abstract
We consider the problem of designing truthful mechanisms for scheduling n tasks on a set of m parallel related machines in order to minimize the makespan. In what follows, we consider that each task is owned by a selfish agent. This is a variant of the KP-model introduced by Koutsoupias and Papadimitriou (Proc. of STACS 1999, pp. 404---413, 1999) (and of the CKN-model of Christodoulou et al. in Proc. of ICALP 2004, pp. 345---357, 2004) in which the agents cannot choose the machine on which their tasks will be executed. This is done by a centralized authority, the scheduler. However, the agents may manipulate the scheduler by providing false information regarding the length of their tasks. We introduce the notion of increasing algorithm and a simple reduction that transforms any increasing algorithm into a truthful one. Furthermore, we show that some of the classical scheduling algorithms are indeed increasing: the LPT algorithm, the PTAS of Graham (SIAM J. Appl. Math. 17(2):416---429, 1969) in the case of two machines, as well as a simple PTAS for the case of m machines, with m a fixed constant. Our results yield a randomized r(1+驴)-approximation algorithm where r is the ratio between the largest and the smallest speed of the related machines. Furthermore, by combining our approach with the classical result of Shmoys et al. (SIAM J. Comput. 24(6):1313---1331, 1995), we obtain a randomized 2r(1+驴)-competitive algorithm. It has to be noticed that these results are obtained without payments, unlike most of the existing works in the field of Mechanism Design. Finally, we show that if payments are allowed then our approach gives a (1+驴)-algorithm for the off-line case with related machines.
Year
DOI
Venue
2009
10.1007/s10951-009-0118-8
J. Scheduling
Keywords
Field
DocType
Scheduling,Approximation algorithms,Truthfulness,Game theory
Approximation algorithm,Mathematical optimization,Job shop scheduling,Scheduling (computing),Computer science,Mechanism design,Game theory
Journal
Volume
Issue
ISSN
12
5
1094-6136
Citations 
PageRank 
References 
10
0.63
13
Authors
4
Name
Order
Citations
PageRank
Eric Angel111614.54
Evripidis Bampis257155.19
Fanny Pascual39714.48
Alex-Ariel Tchetgnia4100.97