6. Business Models:
There are three main business models that maps to the cloud computing architecture layers Those infrastructure as a service, Platform as a service, software as a service, Figure 2 shows the different business models.
Software as a Service: SaaS may be the most widely used form of cloud computing today. Using SaaS your users access shared applications and data over the network or internet typically without having to install or configure anything more complex than a web browser. The advantages is that the users are not required to manage or maintain any aspect of the system, including the backup and recovery of their own data. However, in order to serve as many different groups of people as possible, SaaS provides typically must keep their applications very uniform and standardized, which means the users tend to sacrifice individual flexibility. Examples of SaaS providers include Hotmail, Google Docs, and SalesForce.com
Platform as a Service: PaaS allow your web developers and programmers the ability to upload their content to pre-configured web servers, database servers, and application servers without having to install or maintain any of the server-side applications or operating systems. PaaS providers do not allow full remote control of the underlying server. That means you may be able to develop your application and customize how it operates, but you must still rely on the OS and services patches. Examples of PaaS providers include Google App Engine, Microsoft Windows Azure, and Force.com
|Figure 2: Cloud Computing Business Models|
Infrastructure as a Service: IaaS can give you access to a dedicated virtual or physical workload that you manage and maintain. This allows you to install services and software based on your specific needs, but more importantly it affords you complete control over underlying OS, Including Patches and infrastructure configuration; features that are in accessible in a PaaS or SaaS cloud Offering. Due to the exceptional control that IaaS provides administrators, it is ideally suited for organization with unique compliance or regulatory concerns. In addition, it provides a greater degree of isolation and security between cloud users, because no two organizations share same Virtual machine. Examples of IaaS providers include Amazon AWS, GoGrid and Flexiscale.
There are other Types of business models like disaster recovery as a service, Security as Service…etc. but all of these additional types can be considered as a part of the previous three main types.