How SaaS and DaaS Differ
Organizations are evolving beyond software as a service to outsourced desktops, where service providers own and operate the physical infrastructure that powers virtual desktops while enterprises retain control over the provisioning, management and licensing of the virtual desktops they use.
- SaaS tradeoff: SaaS provides cloud-hosted delivery at the expense of the existing client application model. While SaaS makes sense and has been proven for a number of client-facing applications, only certain classes of applications have been converted into SaaS models; the wholesale replacement of rich Windows applications for enterprises is just not feasible. Conversely, DaaS marries the benefits of a cloud-hosted service with the traditional rich Windows client experience.
- Integration and personalization: Integrating SaaS applications with other, existing applications is quite challenging because of the differences in where they reside and how they're delivered. In addition, IT organizations cannot customize SaaS applications to the same extent as traditional applications. These issues don't exist with DaaS because a user's entire desktop, including all the applications, is kept intact. Applications interact, and can be customized, the way they always have in traditional client computing environments.
- Degree of statelessness: DaaS makes a user's entire desktop stateless. The complete Windows environment-including the applications-roams with the user anytime, anywhere. SaaS only provides statelessness one application at a time.
- Control and security: In a DaaS model, user identity, application servers and organizational data are stored in the enterprise data center, giving you the control and security required. With SaaS, however, data is hosted, along with the application, in the provider's data center, potentially compromising security.
- Architecture supported: SaaS offerings tend to be browser based. DaaS supports all Windows client application architectures (i.e. Win32, .NET, browser based, etc.), allowing organizations to leverage the investments they've made building in-house applications.
- Hosting location flexibility: SaaS is 100% cloud-hosted. DaaS can be hosted either in the cloud (where the physical infrastructure resides in the service provider data center) or in the enterprise data center as a managed service, or both. Companies that have distributed, global infrastructures or that are highly regulated, such as healthcare and financial services organizations, may prefer the managed DaaS model. Businesses that are more centralized or that have less data center capacity may opt for the cloud-hosted DaaS model. Despite the configuration, with DaaS the physical resources are owned and operated by the service provider.