The grid computing is the inevitable development trend and the most important research areas of the parallel computing, distributed computing and high performance computing. The grid workflow technology is one of important research areas in grid computing. Grid workflow technology can use grid resources to complete tasks with the time, space and resources constraints more effectively. The model of grid workflow is the base of the workflow management system, and it is also a method of a grid workflow representation. There are time and data constraint relations in workflow, so we can use the Directed Acyclic Graph(DAG) to represent the workflow scheduling model.It is analyzed for the different objectives of the grid users and the system of grid resources in the grid workflow scheduling, the dissertation proposes a scheduling algorithm based on the bottom level in the load balance and a scheduling algorithm based on the optimal time span in the load balance. Simulations show that those scheduling algorithms can have the optimal time span of the system resources while the load is more balanced. |