Research On Union Navigation Method In Migrating Workflow System

Migrating workflow system is a new kind of technology in the area of workflow management research in recent years. It combines workflow management and mobile computation together, which is very suitable for the distributed concurrent process management in which huge data needs to be transmitted and many remote services need to be invoked frequently. The migrating workflow system contains three elements, which are migrating workflow management engine, workplace and migrating instance (MI). The migrating workflow management engine is responsible for the definition of workflow processes, generation of MI and coordination of multiple-MI; the workplace provides services for the MI, in order to make the MI migrate continuously in many workplaces to complete the workflow task; The MI, built on mobile agent technology, is the execution agent of tasks. Due to advantages such as its support to business process execution with an offline workflow engine as well as reducing network load and network latency, it has drawn considerable attention of people in both the laboratory and the business.In the process of migrating workflow, MI needs to migrate in different workplaces, and the migration strategy ensures migrating instance to complete its task correctly and efficiently in different workplaces. In migrating workflow, the effective execution of the MI is mainly guaranteed by its itinerary graph. The generation of itinerary graph requires the information of the global states of the workplaces and the services they offer, it is a burden to the distributed workflow environment, so we need another method to guide the MI to work correctly and efficiently.The migration strategy based on union navigation for migrating workflow is brought out in this paper. The workplace and its business acquaintances form a union according to their familiarity. The union can accomplish one or more tasks of the MI, can guide the MI migrate to the business acquaintances of the current workplace to execute a task. With the help of union cooperative navigation, the MI can finish the tasks efficiently and correctly.In order to make the migrating workflow system to support cooperative navigation, the definition of the workplace and the MI is extended in the migrating workflow system. The structure of the workplace that supporting cooperative navigation is given and cooperative navigation service is added in the paper.The union navigation method based on distributed planning graph is brought up in this paper. Distributed planning graph can fully utilize the knowledge of the workplaces, and according to the familiarity and other prior knowledge, the most suitable task decomposition methods and services are chosen. According to the cooperative navigation of all the workplaces, this method can get the navigation suggestion which gives out a series of service of the workplaces to accomplish the task to guide the MI.Based on Union Navigation method, the design and implementation of the union navigation modules is carried out. The union navigation module receives navigation request, with the interaction with the local service and familiarity information, then gives out the navigation suggestion.This method is a key method about migration strategy in migrating workflow research. Experiments prove that the method can effectively solve the problem that needs to know the prior knowledge predicatively and can give out the migrating advice in polynomial time which makes the MI accomplishes the task correctly.