Engineering Multi-Tenant Software-as-a-Service Systems

Increasingly, Software-as-a-Service (SaaS) is becoming a dominant mechanism for the consumption of software by end users. From a vendor's perspective, the benefits of SaaS arise from leveraging economies of scale, by serving a large number of customers ("Tenants") through a shared instance of a centrally hosted software service. Consequently, a SaaS provider would, in general, try to drive commonality amongst the requirements of different tenants, and at best, offer a fixed set of customization options. However, many tenants would also come with custom requirements, which may be a pre-requisite for them to adopt the SaaS system.