There are two architectural models – commonly referred as SAAS Maturity models- that describe the transition of a service to what is called Multi-tenant efficient, highly scalable application. The SAAS Maturity model described by Microsoft has four distinct stages and is illustrated below. Another similar well-known model for SaaS-maturity is known as Forrester-model but adds another stage known as "Dynamic Business Apps-as-a-service". The three key Attributes of a SAAS Architecture: Configurability: Metadata used to configure the way the application behaves for customers Multi-tenant Efficiency : Maximizing the sharing of resources across tenants Scalability: Maximizing concurrency, resource efficiency SAAS Simple Maturity Model (Microsoft, 2006) SaaS Maturity Model (Forres