Study On Active Service Method In Goaloriented Migrating Workflows

Migrating workflow is an emerging technology that applies the mobile-agent computing paradigm to workflow management. Different from the traditional workflow model, migrating workflow is a process in which one or more migrating instances migrate continuously and utilize local workflow service to execute their tasks. Migrating instance is a performing agent of tasks. Work place is mapped to the network node, which is one of workflow participants. The set of all work places is called as migrating workflow environment in the workflow alliance, which is called the single work place environment in this thesis. Research in the field of process-oriented migrating workflows has primarily focused on workflow specifications. However, inherent structurized attributes in workflow specifications will limit the flexibility of migrating instances to solve questions inevitably, and reduce the compatibility to the dynamic environment.In order to overcome the shortage of workflow process-oriented approach, migrating instances run with workflow specifications in the goal-oriented migrating workflow. The migrating workflow goal is realized by migrating instace's service discovery or work place's service recommendation (Migrating instances are recommend with work place and workflow resource is called migrating workflow active service in this thesis). A complex business goal is composed by a number of sub-goals. For different business processes goals, different migrating instances generat and run in the work place. Therefore, goal-oriented migrating workflow improves workflow system's flexibility to adapt to dynamic environment, especially for the concurrent distributed business processes.This study was mainly supported by the National Natural Science Foundation of China under Grant and based on the migrating workflow framework proposed by professor ZENG This thesis focused on the methods of goal-oriented migrating workflow active service: a conformation method of the goal-oriented migrating workflow service environment based on business acquaintance domain, a migrating instance service navigation method for goal-oriented migrating workflow, a resource service recommendation method for goal-oriented migrating workflow and a profit allocation method of multi-service-agent for goal-oriented migrating workflow. The study has also built experiments to validate the conclusions.The main contributions of this thesis are described as follows:1. A conformation method of active service environment for goal-oriented migrating workflows.Aiming at the question of insufficient active service ability of single "work place, this thesis borrowed the "small world phenomenon" of the social groups and provided the method of constructing the active service environment for workflows. The basic idea of this method is: Firstly, based on the member cooperation's type and the nature, members of migrating workflow will be divide into the goal-oriented "small world"sets (called service acquaintance domain); Then through the members of service acquaintance domains cooperating, the workflow member sets will be mapped as a service acquaintance network, which is called as active service environment for goal-oriented migrating workflow. In this thesis, we discussed the nature of service acquaintance domain, gave the strategy of construction and evolvement of acquaintance domain. Moreover, the experiments indicated that the active service based on the business acquaintance domain has the higher service ability than sigle work place.2. A service navigation method for goal-oriented migrating workflows.Service navigation means the current work place recommend the next work place for migrating instance. The navigation agent in the work place has a full or part workflow view. This thesis only studied on the navigation agent lacking of full workflow view. In order to meet the rich of services for the goal-oriented migrating workflow, we established POMDP method. This thesis proposed a service navigation model with the business acquaintance mechanism in partially observable environment, analysed service actors to meet the users, gave a service navigation strategy and proposed the arithmetic to build a service navigation cable. The experiment indicated that the sevice navigation based on service acquaintance domain did not enable migrating instance to get lost.3. A resource service recommendation method for goal-oriented migrating workflows.In goal-oriented migrating workflows model, resource service recommendation means the workflow resources such as data, procedures, tools and users, which are satisfied with the workflow goal, are recommendated to migrating instances by work places. If workflow resource services are limited, the workflow speed will be affected or stagnated. Aiming at the question which resource service is insufficient in single work place, this thesis provided a method of the resource service recommendation based on muliti-service agents for goal-oriented migrating workflows. In order to realize resource services were shared between members, we studied the member discovery and the group organization's communication protocol. The experiment indicated that the communication protocol enhanced resource service recommendation efficiency and reliability effectively.4. A profit allocation method of multi-service agents for goal-oriented migrating workflows.Active service based on the business acquaintance is one kind of multiagent union to active service essentially in migrating workflows. In order to guarantee the stable cooperationIn between the multiagents, this thesis studied the stratgy of multi-service agents profit allocation. The basic idea of this stratgy is that multi-service agents allocate profit for a business service net is formulated as a dynamic cooperative game. Though finding Markov perfect equilibrium solution of the dynamic cooperative game, corresponding compensation was computed. Using this compensation information, a profit allocation algorithm was designed. The results of the experiments showed that the profit allocation algorithm could achieve a multi-win Pareto-Optimal outcome, which makes active service tending to be more stable.The main innovative contributions of this thesis are:1. Aiming at the question of insufficient active service ability of single work place, a conformation method of active service environment based on the business acquaintance domain for goal-oriented migrating workflows was proposed.The service acquaintance domain is a goal-oriened member subset of workflow alliance, which is builted and evolved according to the "small world" nature. Service acquaintance network which are interconnected by the service acquaintance domains cover all members and services of workflow alliance. Service acquaintance network may guarantee that the migrating instance has the dynamic work environment which the goal may reach. Compares with the single work place environment, service acquaintance domain not only has stronger multiagent union service ability, but also enhances the efficiency of workflows.2. Aiming at the question that service agent of business acquaintance domain has part workflow view, a service navigation method in partially observable environment for migrating workflows was proposed.In the goal-oriented workflow model, the workflow view of service acquaintance domain is the navigation agent can only observe partial workflow view, which is called as partially observe environment. Comparing with service navigation model and the algorithm based on the overall workflow view, the navigation method in partially observe environment could not only reduce the design difficulty of the multi-organizations and the large-scale workflow management system effectively, but also enhance the efficiency of workflows.3. Aiming at the question of the cooperative stability of service acquaintance domain, a strategy of multi-service agents profit allocation for goal-oriented migrating workflows was proposed.Service agents in the service acquaintance domain are rational workflow participants. They are pay attention to their profit while pursuing the workflow global goal. Therefore, the reasonable profit allocation is a foundation to maintain the service acquaintance domain stable. Comparing with the existing research results, this thesis proposed the strategy of multi-service agents profit allocation based on the dynamic cooperation game, which had made up the existing strategy. The strategy realized the optimized profit assignment among service agents and keeped the cooperation stability of service acquaintance domainThe author proposes the following future works: The service acquaintance network's evolved strategy will be established to support unusual processes and breakdown restores, which enhances the accessibility and the reliability of migrating workflows. Build a method of navigation cable based on service acquaintance domain to eliminate the recommendation difference between navigaition goal and method, which will improve the toughness and the efficiency of service navigation.