• 1 Université des sciences et de la Technologie d'Oran Mohamed Boudiaf [Oran]

In order to get a better performance in distributed systems, load balancing problem has been extensively studied in recent years. Most of existing works focus on traditional systems where resources are generally homogeneous, like clusters. For grid infrastructures, this assumption is not totally true because resources of a grid are highly heterogeneous. Hence, load balancing problem for grid computing is a new challenge for scientists. In this paper, we propose a tree-based representation model for grid computing, over which we develop a hierarchical load balancing strategy. The main characteristics of this strategy can be summarized as follows:(i) It uses a task-level load balancing; (ii) It privileges local tasks transfer to reduce communication costs; (iii) It is a distributed strategy with local decision making.