As Web services start to be deployed for mission critical applications and for e-Business scenarios, higher Quality of Service (QoS) and continuous service delivery become a critical issue to ensure high availability and reliability in spite of the failure or unavailability of the participating services or networks. These challenges call for vast improvements in the Web services containers and the mediation infrastructure. To address these requirements, we propose Web Services Message Bus (wsBus), a lightweight service-oriented middleware for reliable and fault tolerant Web services interactions. This paper first discusses wsBus architecture and features and then it reports some experimental results to illustrate the effectiveness of wsBus in adding reliable and uninterrupted services to a supply chain management system.