Worst-case analysis of the WSPT and MWSPT rules for single machine scheduling with one planned setup period

2008 ◽  
Vol 187 (3) ◽  
pp. 1080-1089 ◽  
Author(s):  
Imed Kacem ◽  
Chengbin Chu
2015 ◽  
Vol 32 (02) ◽  
pp. 1550002 ◽  
Author(s):  
Jan-Yee Kung ◽  
Ming-Hung Shu

Job learning and deterioration coexist in many realistic machine-job scheduling situations. However, in literature, the constructed forms of the machine scheduling models with job learning and/or deteriorating effects were specific types of functions, which constrained their applicability in practice. This paper introduces a new single-machine scheduling model, where the actual processing time of a job is a general function of its starting time as well as scheduled position, which shows a broad generalization in contrast to that of certain existing models. For three objectives corresponding to the single-machine scheduling problem–total weighted completion time, discounted total weighted completion time, and maximum lateness — this paper presents their respective approximation result on the basis of the worst-case bound analysis from the optimal algorithm. The results demonstrate that under our proposed model, minimization of scheduling operations such as the makespan, sum of the kth power of completion times, and total lateness are polynomially solvable. Moreover, under some feasible conditions for the scheduling parameters, the minimum optimization problems of the total weighted completion time, discounted total weighted completion time, maximum lateness, and total tardiness are all recognized as polynomial forms and their solutions are provided.


2008 ◽  
Vol 25 (01) ◽  
pp. 1-10 ◽  
Author(s):  
LINGFA LU ◽  
JINJIANG YUAN

In the single machine scheduling problem with job delivery to minimize makespan, jobs are processed on a single machine and delivered by a capacitated vehicle to their respective customers. We first consider the special case with a single customer, that is, all jobs have the same transportation time. Chang and Lee (2004) proved that this case is strongly NP-hard. They also provided a heuristic with the worst-case performance ratio [Formula: see text], and pointed out that no heuristic can have a worst-case performance ratio less than [Formula: see text] unless P = NP. In this paper, we provide a new heuristic which has the best possible worst-case performance ratio [Formula: see text]. We also consider an extended version in which the jobs have non-identical transportation times and the transportation time of a delivery batch is defined as the maximum transportation time of the jobs contained in it. We provide a heuristic with the worst-case performance ratio 2 for the extended version, and show that this bound is tight.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xuefei Shi ◽  
Dehua Xu

We consider a single machine scheduling problem with multiple maintenance activities, where the maintenance duration function is of the linear formft=a+btwitha≥0andb>1. We propose an approximation algorithm named FFD-LS2I with a worst-case bound of 2 for problem. We also show that there is no polynomial time approximation algorithm with a worst-case bound less than 2 for the problem withb≥0unlessP=NP, which implies that the FFD-LS2I algorithm is the best possible algorithm for the caseb>1and that the FFD-LS algorithm, which is proposed in the literature, is the best possible algorithm for the caseb≤1both from the worst-case bound point of view.


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