  Software as a Service cloud computing model favorites the Multi-Tenancy as a
key factor to exploit economies of scale. However Multi-Tenancy present several
disadvantages. Therein, our approach comes to assign instances to multi-tenants
with an optimal solution while ensuring more economies of scale and avoiding
tenants hesitation to share resources. The present paper present the
architecture of our user-aware multi-tenancy SaaS approach based on the use of
rich-variant components. The proposed approach seek to model services
functional customization as well as automation of computing the optimal
distribution of instances by tenants. The proposed model takes into
consideration tenants functional requirements and tenants deployment
requirements to deduce an optimal distribution using essentially a specific
variability engine and a graph-based execution framework.
