Holistic SLA Ontology for Cloud Service Evaluation

With the evolution of service computing ecosystems and the promises of the Cloud, there is an increasing need for service evaluation and monitoring across a wide range of QoS dimensions. Although in the literature service monitoring is tightly coupled with Service Level Agreement establishment, existing approaches do not provide a holistic model for Cloud service evaluation. In this paper, we present an SLA ontology, encompassing the whole service lifecycle, in order to drive and improve the evaluation of services. We propose a common QoS ontology to express specifications, requirements and feedback. Based on this, we introduce a symmetric representation of service monitoring information and human feedback, allowing a unified management of the service evaluation. Finally, the SLA ontology supports the profiling of users, enabling a refined reputation calculation through the dynamic consideration of customer segments.