Abstract: The hierarchical architecture of an Enterprise Service Bus (ESB) based BPM environment,NpuESB,was proposed in this paper. NpuESB is a rapid BPM application development platform grounded on the infrastructure of JBI specification-compliant distributed ESB. By introducing ultra server and process management module, NpuESB enables centralized management of the ESB environment and BPM application workflows. Workflows in ESB environment can be modeled with the formal method based on Pi calculus proposed in this paper. Some important design and implementation considerations for the distributed ESB and management tools were also discussed. Application tests of the prototype system demonstrate NpuESB's effectiveness. Compared with traditional techniques and tools, NpuESB delivers better flexibility and scalability meanwhile stays compatible with legacy systems, thus reduces EAI application development and maintenance costs to a greater extent.

Key words: Eterprise service bus, Enterprise application integration, Service oriented architecture