Layered Apporach -cloud computing

First Layer – Cloud Computing
The first layer is all the computing power and resources that enterprises need to deliver a service or application, including storage, processing, networks and servers. Some cloud services may use all of these components; others just one or two. This layer is the same as cloud computing
Cloud computing converts the traditional capital expenditure model (CapEx) common in data centers today to an operational expenditure (OpEx) model
Cloud computing is different. It is a specific type of utility computing. Cloud computing is the IT environment—encompassing all elements of the full “stack” of IT and network products (and supporting services)—that enables the development, delivery and consumption of cloud services. Properly defined,
Cloud computing has three key technical characteristics:
• Scale: cloud computing systems incorporate tens of thousands of servers, offering processing power vastly greater than a traditional data center.
• Flexibility: cloud computing can be used to handle very small or large processing tasks, and can be adjusted in real-time to match demand. If an organization needs 10 servers one day and 5,000 the next, the cloud can handle such a dynamically varying request.
• Efficiency: unlike traditional data centers, clouds offer pooled computing power, performing like a single large machine. Sharing tasks across this pool reduces costs and massively improves processing speeds.

Second Layer – Cloud Platform
The middle layer is a platform that enables the enterprise to add specific services that rely on the cloud computing layer for their power. Example platforms include Google Application Engine or Microsoft’s Azure, which provide platforms that are available to developers running services that draw on generic and custom functions. Enterprises would possibly use different platforms for different situations— for example, a platform supplied by a company such as HP, IBM, Dell to manage access to all the technology services in the first layer of the cloud, and a subsequent layer from a company such as TCS to provide industry specific “services” for processes in the third and final layer
Third Layer – Cloud Services
This final layer comprises the cloud services themselves. Services may be internally or Externally facing, and may be developed by the enterprise itself or by a third party. Many services will combine elements of both approaches. For example, companies can use Yahoo!’s FireEagle location service and combine it with their own GPS tracking data to create a shipment tracking service. The resulting service could also be combined with an internal HR service to monitor working hours for drivers to create an entirely new service.

This third layer is important because this is where businesses can differentiate Themselves in a SOA and cloud environment—by buying services, adding value and Selling them, companies can create enormous flexibility and competitive advantage
Cloud services provide the automated processes that are delivered using cloud computing. Cloud services are a specific type of Software-as-a-Service (SaaS)
Cloud Services allows CIOs and CFOs to control costs through these hardware and software leasing environments.
Cloud services used internally through SOA, providing greater efficiency, flexibility and cost-effectiveness
Extensibility: Cloud services can be modified and customized using SOA techniques
Matching Expectations: Cloud services require clear SLAs; deploy these using SOA contract-management techniques
Hardware alone is insufficient to support mission critical or traditional IT data center use of these new operating models. Cloud Services provides the vital layer enabling organizations to leverage PaaS offerings in support of an evolutionary, low-risk transition to SaaS-based COBOL applications, providing the expected level of scalability, security and availability, and meeting service level agreements with the users of such core enterprise systems.
Using Cloud Services, these applications will then be based on the very same code as their other supported platforms, ensuring maximum reach with minimal impact on development.
Cloud Services provides the compatible environment in which to host mission critical business systems.