Abstract
The 3-layer workflow scheduling model consist of front layer, outside scheduling layer and inside scheduling layer, it can describe the task scheduling more clearly than conventional models. This paper mainly discusses the improved Dijkstra algorithm with multi-precondition, which is the core of this model, converts the classical Dijkstra algorithm into an useful way to calculate the shortest path in weighted directed graph with multi-precondition. The experiment proved out the 3-layer workflow scheduling model based on improved Dijkstra algorithm an efficient model.