Clearing the sky : understanding SLA elements in cloud computing

Issues characterizing cloud computing such as security, interoperability, and vendor lock-in are likely to act as inhibitors of the widespread adoption of cloud computing in organizations. These issues call for relational and contractual mechanisms to articulate the desired outcomes of service provisioning and acceptable behavior of service recipients and providers. In this paper we focus on the contractual mechanisms for this purpose and, more specifically, Service Level Agreements (SLA). We have conducted a qualitative study interviewing industry experts to understand the extent to which SLA specifications in traditional IT services outsourcing can be applied in cloud computing, identifying elements becoming redundant or not applicable, and new elements capturing the specificity of the business relationships entailed by cloud computing. Our study results in a detailed SLA specification for different cloud computing deployment models, i.e. private and public cloud, and in a framework investigating the role of SLA elements in the decision making process for cloud computing outsourcing.