this paper presents a mathematical model for a flow shop scheduling problem consisting of m machine and n jobs with fuzzy processing times that can be estimated as independent stochastic or fuzzy numbers. in the traditional flow shop scheduling problem, the typical objective is to minimize the makespan). however,, two significant criteria for each schedule in stochastic models are: expectable m...

to use services transparently in a distributed environment, the utility grids develop a cyber-infrastructure. the parameters of the quality of service such as the allocation-cost and makespan have to be dealt with in order to schedule workflow application tasks in the utility grids. optimization of both target parameters above is a challenge in a distributed environment and may conflict one ano...

this article addresses a multi-stage flowshop scheduling problem with equal number of unrelated parallel machines. the objective is to minimize the makespan for a given set of jobs in the system. this problem class is np-hard in the strong sense, so a hybrid heuristic method for sequencing and then allocating operations of jobs to machines is developed. a number of test problems are randomly ge...

In this work we give a tight lower bound on makespan approximations for envy-free allocation mechanism dedicated to scheduling tasks on unrelated machines. Specifically, we show that no mechanism exists that can guarantee an envy-free allocation of jobs to m machines with a makespan of less than a factor of O(logm) of the minimal makespan. Combined with previous results, this paper definitively...

We consider scheduling problems in the master slave model, which was introduced by Sahni in 1996. The goal is to minimize the makespan and the total completion time. It has been shown that the problem of minimizing makespan is NP-hard. Sahni and Vairaktarakis developed some approximation algorithms to generate schedules whose makespan is at most constant times the optimal. In this paper, we sho...

Distributed systems have been an active research area in computer science for the last decade, task allocation and load balancing have been a major issue associated with such systems. The load-balancing problem, attempts to compute the assignment with smallest possible makespan (i.e. the completion time at the maximum loaded computing node). Load balancing problem is a NP hard problem. This pap...

It has become more and more important and difficult to minimize makespan in the global competitive markets. The purpose of this paper is to develop a decision support system to assist managers in making decisions for minimal makespan. There are too many and complex factors for senior managers to make suitable decisions. By traditional methods to allocate orders for minimum makespan, it often ma...

This paper investigates the scheduling problems in which the job processing times do not remain constant but are increasing linear functions of their starting times. Two deteriorating scheduling models, Model 1 and Model 2, for multiple machines are considered, with the goal being to minimize the makespan. In this paper, we propose an efficient heuristic for Model 1 and prove that the ratio of ...

In this paper we analyze the robustness of 20 static, makespan-centric, DAG scheduling heuristics of the literature. We also study if dynamically changing the order of the tasks on their assigned processor improves the robustness. Based on experimental results we investigate how robustness and makespan are correlated. Finally, the heuristics are experimentally evaluated and ranked according to ...