Capturing Customers´ Requirements towards Mixed-Tenancy Deployments of SaaS-Applications

Software-as-a-Service (SaaS) is a delivery model whose basic idea is to provide applications to the customer on demand over the Internet. In contrast to similar but older approaches, SaaS promotes multi-tenancy as a tool to exploit economies of scale. This means that a single application instance serves multiple customers. However, a major throwback of SaaS is the customers´ hesitation of sharing infrastructure, application code, or data with other tenants. This is due to the fact that one of the mayor threads of mixed-tenancy is information disclosure due to a system malfunction, system error, or aggressive actions by individual users. So far the only approach in research to counteract on this hesitation has been to enhance the isolation between tenants using the same instance. Our approach (presented in earlier work) tackles this hesitation differently. It allows customers to choose if or even with whom they want to share the application. The approach enables the customer to make that choice not just for the entire application but specifically for individual application components (AC). One of the challenges towards the realization of a mixed-tenancy platform is the capturing of customer requirements. This is why the focus of this paper is to present an approach that enables tenants to express their unique deployment needs. This approach is realized using Semantic Web technologies.