Abstract
Cloud computing is an emerging topic in the information technology sector. The rapid evolution of this technology led to the emergence of new interaction models between its actors. However, the absence of a universally accepted format of the service level agreement (SLA) governing the relationships between the different actors of cloud increases its complexity. In addition, the dynamic nature of the cloud could lead to severe SLA violations. This undesirable but currently unavoidable situation may lead to penalizing providers and forcing customers to evaluate their SLAs permanently. In this paper, we propose a generic and semantically richer ontology-based model for SLA to improve its definition and its evaluation in cloud computing. Through this model, we have developed a prototype to validate our model and our monitoring process where SLA evaluation and guarantee actions triggering are automatically performed.