The realization of the semantic web vision depends not only on the ability of the Internet users to associate detailed semantics with resources with different ontology, but equally importantly, on the availability of adequate tools and mechanisms to allow users to discover, access, and share resources among their communities of interests in an efficient manner. To this end, the paper presents a Personalized Web Service Architecture (PWSA)to support the automation of personalized workflow advertising and discovery. The basic tenet of the architecture is the concept of active service workflows, whereby semantic-aware agents, referred to as flowlets, enable the execution of web service process, based on a user-defined rules and personalized interests and the Web services specification. Two schemes are used to support personalized workflows. In the first scheme, the flowlet uses a centralized approach for workflow execution. The second scheme, uses a decentralized 'routing slip' approach to orchestrate web services. The centralized scheme provides a more robust and secure mechanism to perform web service workflow. In particular, the scheme can efficiently detect and deal with failure and malicious behavior occurring in each step of the workflow. The decentralized scheme uses communication bandwidth more efficiently to achieve service orchestration.