In order to solve the bottleneck existed in the central controller of centralized service composition, a method of constructing decentralized service composition based on process partitioning was proposed. Firstly, the business process was modeled by the type directed graph. Then, a grouping algorithm was proposed based on the graph transformation method, and the process model was partitioned according to the grouping algorithm. Finally, the decentralized service composition was constructed according to the partitioning results. Test results show that compared with single thread algorithm, the grouping algorithm has the time-consuming for model 1 reduced by 21.4%, and the decentralized service composition constructed has lower response time and higher throughput. The experimental results show that the proposed method can effectively partition the business processes in the service composition, and the constructed decentralized service composition can improve the service performance.

Concerning the problem of describing and analyzing dynamic behavior of the categorical model of nested-style structure, a Port Automata based behavioral expression Method (PAM) was proposed. The method was based on system states, input and output ports to define computations on object and structure. And it has been proved that PAM is a functor, which means that PAM is a structure preserved computation. Under the help of PAM, typical composite behaviors (including parallel, serial, and feedback) and application issues were discussed. The relevant results show that PAM can be applied in describing and analyzing dynamic behavior of systems with nested structure.