Research on Dynamic Service Composition Based on Object Petri Net for the Networked Information System

In contrast to a typical pyramid information system, resources and services in a networked information system are often distributed, published, accessed and updated by multiple service providers. The networked information systems need to support the logistical aspects of business processes at hand. How to invoke these services to satisfy the users´ requirement? A lot of research work has been done in the fields of service discovery and service composition. A feasible method is making use of service API schema classification to inquire suitable service, and then designing a workflow mechanism to consume a serial of services on the fly. But this method cannot guarantee the high service recall and precision rate. And up to now there is no appropriate method to realize the dynamic service composition. Object Petri Nets (OPN) are a well-founded process modeling technique which have been used to model and analyze several types of processes including protocols, manufacturing systems, and business processes. This paper brings forward dynamic service composition based on OPN for networked information system. A service behavior is basically a partial ordered set of operations, which can interact with each other by standard network protocol and interface. The paper brings forward the mapping rules from service to Object Petri Net, based on which the eight tuple description is presented. Secondly the five basic service composition models of sequence, alternative, parallel, arbitrary sequence, iteration are determined, and the mathematical characteristics are studied. Finally the paper brings forward service dynamic composition flow chart. Through the research on dynamic service composition based on OPN, it is adaptable to model and simulate for the networked information system.