Research On Key Technologies For Cross Enterprises Cooperation Based On Services Composition

As the development of economic globalization and the progress of information technologies, large scale information applications are taking a more and more important character in the economic society. Enterprises need to align themselves to the rapid changing market and adjust their business destinations. How to turn enterprise applications into services oriented and to be changed dynamically becomes the dominating problem in today's software industry. Service oriented architecture and Web Service technology come into real in such background. Web services have the advantages of platform independence, loosely coupling and reusability so that they have very large of application values in enterprises including legacy system migration, heterogeneous systems integrations and crossing enterprises business cooperation.Currently, the industry standards of Web services are being continuously improved; methods and technologies for services composition are receiving considerable attentions. However, it still remains a lot of unresolved problems while adopting them into enterprise applications to make them work correctly, safely and efficiently. The researches in this paper take cross enterprises business cooperation based on services composition as the application background, focus on the runtime problems of service composition execution such as correctness verification, access control and performance optimization. Major work and contributions include:1) A formalized modeling and verification method for business processes based on Petri Net is proposed. The business cooperation between businesses partners usually contain complicated business logics and message exchanges. The static restriction methods based on interface compatibility cannot guarantee the correctness of dynamic behaviors of processes. This paper proposed a consistent model for control and data interface of web services based on Petri Net theory. The basic construction units of services composition is formalized descripted with this model. The soundness of service workflow net is defined to descript the correctness of composited services. The business cooperation process is modeling based on this definition and an analysis algorithm for the verification of correctness and compatibility for composite services is proposed. Availability of the algorithm is evaluated by several cases.2) A dynamic multiple domains access control model base on role based access control (RBAC) was proposed. The existing single domain based access control model cannot fulfill the authorization requirements for service compositions cross multiple enterprises. The process structures of composite services were analyzed and a role mining algorithm was proposed to find the role set with minimized permissions that meet the access requirements of composite services. Authorization negotiations were set up among relevant domains for each cross domain operation in composite services and cross domain role mappings were built according the mined role sets with minimized cost to fulfill the cross domain operations. Based on this model, a runtime framework aligned with current industry standard was proposed to authorize dynamically based on the current running status of composite services. Simulation experiments showed the effectiveness of key part of the role mining algorithm.3) A services deployment strategy is proposed for performance optimization of cross enterprise service compositions. The cross enterprise business cooperation uses public network as its information delivery infrastructure. The unstable nature of public network, the geographical and network locations distributions and the deployment of security policies of each enterprise brings non negligible effect on the performance of composited services. Execution cost of composited services is considered as the optimization objective and a concept named interaction dependency is proposed. The performance is optimized based on adjusting the deployment domains of component services in order to reduce the overall execution costs. With the limitation of deployable domains of services, the problem is converted into an optimization problem under multiple restrictions, and a genetic algorithm based method is proposed to resolve this problem. The simulation experiments show the algorithm has considerable improvement in different scenarios.