The scope of IMS QoS management is limited to session initialization and QoS provisioning, thus lacking follow-up or monitoring functionality; neither does it tackle user differentiation. A tempting approach would be to leverage the standard 3GPP architecture by Assurance services based on TMForum's eTOM framework. This scenario would however expose a set of general business processes and would require a projection of IMS processes towards the eTOM. The work presented here follows this strategy, providing monitoring functionality to IMS services based on eTOM processes able to provide SLA assessment and Assurance services. The distributed architecture involves the BPEL language for orchestration and SOA components