Research On Process Network Based Cooperative Computation Model Of Services

Recently, Service-Oriented Architecture (SOA) has drawn a lot of attention. It is a kind of new distributed application architecture and component technology and will be promoted in the industry as the next evolutionary step in software architecture to help IT organizations meet their ever more complex set of challenges. In this architecture, all functions are defined as independent services with well-defined interfaces which can be called in a predefined sequence to form business processes. Services can be seen as platform-independent, loosely-coupled software modules with well defined functionality that are distributed over the Internet. Service-Oriented Computing (SOC) is a new computing paradigm that utilizes services as the basic constructs to support the development of rapid, low-cost and easy composition of distributed applications even in heterogeneous environments. According to computing approaches, the current service computing models are categorized as syntactic approach, semantic approach and formal approach. Syntactic approach emphasises the workflow process during composition. Semantic approach aims at fully automating all the stages of the Web services lifecycle. Formal approach is effective at verifying service composition.This paper proposes a CCM called process network based cooperative computation model of services. On the one hand, CCM adopts syntactic approach to describe and compose services, it inherits the advantage of syntactic approach in describing workflow composition process; On the other hand, CCM employs the advantage of formal approach in verifying service composition and adopts formal verification mechanism provided by CCS process algebra to verify correctness of service composition. KPN process network (KPN) is a model of computation based on dataflow and commonly used for describing a set of cooperative processes that communicate with each other using FIFO buffered channel. KPN's basic properties, including concurrency, scheduling, determinacy, hierarchy and executable make it a perfect theoretic model for service computing. But KPN's inadequateness in modeling...