As more enterprises are looking at software-as-a-service (SaaS) solutions, Microsoft has augmented LitewareHR, their SaaS reference application, to include the Software + Services (S+S) model. Enabling the integration of local and "in the cloud" software, S+S allows for the disconnected and offline scenarios lacking in today's hosted solutions. Made popular by Salesforce.com, SaaS is moving out of the early adopter phase and is now on the radar of many CIOs and ISVs. The MSDN Solution Architecture Center describes SaaS as follows:
Gianpaolo Carraro, the director of SaaS architecture in the Architecture Strategy team at Microsoft outlined the architectural challenges demonstrated in the release:
For decades, companies ran their software on their own infrastructure. Software as a Service is a new delivery model where companies pay not for owning the software itself but for using it. In the SaaS scenario, a software provider is responsible for its availability (maintenance, scalability, disaster recovery, etc.). That's what the companies pay for.This release of LitwareHR "includes enhanced backend functionality, a new Smart Client and integration with Silverlight Streaming". Architects will greatly benefit from the new package that will help them "assess performance and scalability of databases with different extensibility patterns [like] extension tables, fixed columns and XML data types".
Gianpaolo Carraro, the director of SaaS architecture in the Architecture Strategy team at Microsoft outlined the architectural challenges demonstrated in the release:
- Multi-tenancy
- Application customization: metadata driven application for tenant extensions at the UI, business logic and data access layers.
- Performance and scalability of extensible, multi-tenant applications.
- Service Layer design: functional web services and meta-data web services to enable different consumption experiences ( multi-head application)
- Claims based authorization
- Tenant resource provisioning
