Abstract
With the rapid development of Internet and the gradual maturity of SOA, SaaS has become a popular software service mode. This paper proposes a flexible business process customization framework to solve problems caused byorchestrating SaaS business process through BPEL specifications. The framework is fully independent of BPEL engine and web services, which can realize a series of functions as following: enabling the tenant to customize service and process during defining process, verifying and checking the correctness of process logic while deploying process, modifying dynamically, substituting services andhandling abnormal situations according to the rules provided by tenants or the framework automatically at the runtime of process.