中文摘要：

网格基础设施是目前科学工作流应用规划、部署和执行的主要支撑环境。然而由于网格资源的自治、动态及异构性，如何在保障用户QoS约束下有效调度科学工作流是一个研究热点。针对费用约束下的科学工作流调度问题，为了提高其执行的可靠性，本文使用随机服务模型描述资源节点的动态服务能力并考虑本地任务负载对资源执行性能的影响，给出一种资源可靠性的评估方法，在此基础上提出一种费用约束下的科学工作流可靠调度算法RSASW。仿真实验结果表明RSASW算法相对于GAIN3。GreedvTime-CD及PFAS算法。对工作流的执行具有很好的可靠性保障。

英文摘要：

Grid infrastructures are important supporting environments for scientific workflow application nowadays. However, ensuring that users＇ QoS can be met in dynamic computational Grid as scheduling scientific workflow is challenging. Aiming at guaranteeing the completion of scientific workflow successfully under cost constraint and improving reliability of execution, we used a stochastic service model considering the impact of local tasks to describe dynamic workloads of Grid resources. A corresponding calculation method for resource reliability was proposed. Reliable scheduling algorithm of scientific workflow with cost constraint was presented. Simulations show that the proposed algorithm can improve the executable reliability of scientific workflow efficiently, which can be applied to scientific workflow management system in dynamic Grid environment.