Game of Definitions—Do the NIST Definitions of Cloud Service Models Need an Update? A Remark

Cloud computing captured the world by storm as a cheaper, faster and safer alternative to an on-premises computing environment. Consequently, several organizations started favouring cloud computing service models over traditional on-premises hosting to offer their products or services over the Internet. As cloud computing gained popularity in the early 2000s, the National Institute of Standards and Technologies (NIST) decided to define it in 2011 formally. Since then, almost a decade has passed and cloud technology has progressed by leaps and bounds. As a result of the commercial progress that cloud computing has made as a technological offering, delivery methodologies have evolved and cloud service providers nowadays are using new service models that are not falling in the traditional service brackets of Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS) as defined by the NIST. Serverless and containers are examples of such service models. Consequently, cloud service providers developed novel terminologies like Database as a Service and Storage as a Service to clearly define their offerings. After researching and studying various examples and models, we feel the times have changed. Since the NIST definitions have not been updated since 2011, a lot of confusion has emerged among services that hinder compatibility. In this paper, we put forth the argument to update the definition of cloud service models introduced by the NIST in 2011. The argument is supported by detailing two new service methodologies: serverless and containers and explaining how these do not fit in the buckets defined by the NIST in 2011.