SaaS Dynamic Evolution Based on Model-Driven Software Product Lines

Cloud computing is an emerging paradigm that provides scalable computing and storage capabilities where resources are accessed on a pay-as-you-go basis. Software as a Service (SaaS) applications are hosted in the cloud and made available as services for tenants' organizations over a network. To achieve reusability in cloud computing, software and hardware resources are shared among multiple tenants. Conventional multi tenant SaaS applications provide the same set of services for all tenants thus resulting in one-size-fits-all applications. However, as tenants may have different requirements, customizable SaaS solutions are needed. To accommodate evolving tenants' requirements, the SaaS instance should evolve systematically. In this paper, we present a multi-tenant single instance SaaS evolution platform based on Software Product Lines (SPLs). The platform specifies a set of evolution rules, based on feature modeling, that govern evolution decisions. We also present the early implementation phases of the proposed approach based on SPLs and Model Driven Architecture (MDA) concepts.