Exact analysis of production lines with Coxian-2-distributed processing times and parallel machines

2021 ◽  
pp. 107471
Author(s):  
Özgün Yücel ◽  
Önder Bulut
Keyword(s):  
Parallel Machines ◽  
Distributed Processing ◽  
Production Lines ◽  
Exact Analysis ◽  
Processing Times

Scheduling jobs with normally distributed processing times on parallel machines

2021 ◽  
Author(s):  
Antonin Novak ◽  
Premysl Sucha ◽  
Matej Novotny ◽  
Richard Stec ◽  
Zdenek Hanzalek
Keyword(s):  
Parallel Machines ◽  
Distributed Processing ◽  
Processing Times ◽  
Normally Distributed

scholarly journals Scheduling jobs with stochastically ordered processing times on parallel machines to minimize expected flowtime

1986 ◽  
Vol 23 (03) ◽  
pp. 841-847 ◽  
Author(s):  
R. R. Weber ◽  
P. Varaiya ◽  
J. Walrand
Keyword(s):  
Processing Time ◽  
Parallel Machines ◽  
Preemptive Scheduling ◽  
Total Reward ◽  
Processing Times ◽  
Identical Machines ◽  
Scheduling Strategies

A number of jobs are to be processed using a number of identical machines which operate in parallel. The processing times of the jobs are stochastic, but have known distributions which are stochastically ordered. A reward r(t) is acquired when a job is completed at time t. The function r(t) is assumed to be convex and decreasing in t. It is shown that within the class of non-preemptive scheduling strategies the strategy SEPT maximizes the expected total reward. This strategy is one which whenever a machine becomes available starts processing the remaining job with the shortest expected processing time. In particular, for r(t) = – t, this strategy minimizes the expected flowtime.

SEMI-ONLINE MACHINE COVERING

2007 ◽  
Vol 24 (03) ◽  
pp. 373-382 ◽  
Author(s):  
SHENG-YI CAI
Keyword(s):  
Competitive Ratio ◽  
Completion Time ◽  
Online Algorithm ◽  
Parallel Machines ◽  
Identical Parallel Machines ◽  
Processing Times ◽  
First Case ◽  
Machine Covering

This paper investigates two different semi-online versions of the machine covering, which is the problem of assigning a set of jobs to a system of m(m ≥ 3) identical parallel machines so as to maximize the earliest machine completion time. In the first case, we assume that the largest processing times is known in advance. In the second case, we assume that the total processing times of all jobs is known in advance. For each version we propose a semi-online algorithm and investigate its competitive ratio. The competitive ratio of each algorithm is [Formula: see text], which is shown to be the best possible competitive ratio for each semi-online problem.

Scheduling jobs with exponential processing times on parallel machines

1988 ◽  
Vol 25 (04) ◽  
pp. 752-762 ◽  
Author(s):  
Tapani Lehtonen
Keyword(s):  
Binomial Distribution ◽  
Parallel Machines ◽  
Essential Feature ◽  
Stochastic Order ◽  
Partial Solution ◽  
Flow Time ◽  
Optimal Assignment ◽  
Processing Times ◽  
Expected Makespan

We consider a system where jobs are processed by parallel machines. The processing times are exponentially distributed. An essential feature is that the assignment of the jobs to the machines is decided before the system starts to work. We consider both the flow time and the makespan. In the case of the flow time we allow both the machines and the jobs to be non-homogeneous. The optimization is by minimizing the flow time in the sense of stochastic order and the optimal assignment is obtained for this case. The case of the makespan is harder. We consider the expected makespan and as a partial solution we prove an optimality result for the case where there are two non-homogeneous machines and the jobs are homogeneous. It turns out that the optimal assignment can be expressed by using a quantile of a binomial distribution.

scholarly journals Preemptive Scheduling with Controllable Processing Times on Parallel Machines

2015 ◽  
Vol 3 (1) ◽  
pp. 68-76
Author(s):  
Guiqing Liu ◽  
Kai Li ◽  
Bayi Cheng
Keyword(s):  
Polynomial Time ◽  
Resource Use ◽  
Parallel Machines ◽  
Optimal Algorithm ◽  
Parallel Machine Scheduling ◽  
Controllable Processing Times ◽  
Scheduling Problems ◽  
Processing Times ◽  
Online Problems ◽  
Machine Scheduling Problems

AbstractThis paper considers several parallel machine scheduling problems with controllable processing times, in which the goal is to minimize the makespan. Preemption is allowed. The processing times of the jobs can be compressed by some extra resources. Three resource use models are considered. If the jobs are released at the same time, the problems under all the three models can be solved in a polynomial time. The authors give the polynomial algorithm. When the jobs are not released at the same time, if all the resources are given at time zero, or the remaining resources in the front stages can be used to the next stages, the offline problems can be solved in a polynomial time, but the online problems have no optimal algorithm. If the jobs have different release dates, and the remaining resources in the front stages can not be used in the next stages, both the offline and online problems can be solved in a polynomial time.

Scheduling identical jobs on uniform parallel machines with random processing times

1998 ◽  
Vol 35 (1-2) ◽  
pp. 109-112 ◽  
Author(s):  
Mohamed I. Dessouky ◽  
Richard L. Marcellus ◽  
Li Zhang
Keyword(s):  
Parallel Machines ◽  
Processing Times ◽  
Identical Jobs

On the optimality of LEPT and cµ rules for machines in parallel

1992 ◽  
Vol 29 (3) ◽  
pp. 667-681 ◽  
Author(s):  
Cheng-Shang Chang ◽  
Xiuli Chao ◽  
Michael Pinedo ◽  
Richard Weber
Keyword(s):  
Distributed Processing ◽  
Sufficient Conditions ◽  
Weighted Sum ◽  
Scheduling Problems ◽  
Priority Assignment ◽  
Processing Times ◽  
Weighted Number ◽  
Necessary And Sufficient ◽  
Late Jobs ◽  
Completion Times

We consider scheduling problems with m machines in parallel and n jobs. The machines are subject to breakdown and repair. Jobs have exponentially distributed processing times and possibly random release dates. For cost functions that only depend on the set of uncompleted jobs at time t we provide necessary and sufficient conditions for the LEPT rule to minimize the expected cost at all t within the class of preemptive policies. This encompasses results that are known for makespan, and provides new results for the work remaining at time t. An application is that if the cµ rule has the same priority assignment as the LEPT rule then it minimizes the expected weighted number of jobs in the system for all t. Given appropriate conditions, we also show that the cµ rule minimizes the expected value of other objective functions, such as weighted sum of job completion times, weighted number of late jobs, or weighted sum of job tardinesses, when jobs have a common random due date.

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