Delivering end-to-end QoS is emerging as a key requirement for the success of innovative mobile data services. However, overall service quality tends to be susceptible to variations in the performance of mobile networks. SPs (service providers) will need to know what performance and QoS parameters are important in a service delivery chain, and how they can be measured and aggregated to build an overall picture. This is proving to be challenging and placing new requirements on traditional OSSs (Operations Support Systems). For example, OSS process flows involved in SLA (Service Level Agreement) violation monitoring are markedly more complex. Consequently, OSS functions are more interdependent. There is a need to map out and define such interdependencies. This paper presents an OSS architecture that enables QoS reporting and SLA violation monitoring. Key OSS functions are defined and an information model capturing QoS requirements is presented. The results of the implementation and validation of the architecture are also presented.