If a component delivers a service over a network using a service-oriented infrastructure, the Open Group now explains, in whatever form that takes, the concept will be referred to as XaaS. Literally, the X stands for... anything.

"This is the essence of cloud computing," reads the Open Group's new Service-Oriented Cloud Computing Infrastructure (SOCCI) framework. "It refers to an increasing number of services that are delivered over a network. Anything as a service requires an understanding of the service objectives and the accounting of service use and quality. The objectives, use, and quality can be determined from the underlying reference model for SOI: Broad network access (cloud) + resource pooling (cloud) + business-driven infrastructure on-demand (SOI) + service-orientation (SOI) = XaaS."

SOCCI is a necessary adaptation to the OG's existing SOI concept, mainly because certain aspects of cloud services had become incongruous with the formal framework for SOI even up until last week. The expectation for SOI was built around software contained within the fixed space of server hardware (note: no virtualization) in an enterprise data center, or perhaps (begrudgingly) through cohosting services. Resources were provisioned directly and manually by administrators, and financing was often expected to be handled as capital expenditures.

The new SOCCI framework embraces the modern understanding of cloud services as spelled out by the National Institute of Standards and Technology. There are three principal divisions - SaaS, IaaS, and PaaS - and usually anything else that vendors may attach to an "-aaS" is arbitrary and often self-serving. Open Group leaves the door open for something else to fit there later, but makes clear that these three pillars are the only ones that need to hold up the cloud for now.

Previously, the SOI framework helped organizations to understand how to design, using architecture, the hardware foundations for their services. With cloud computing, much of that architectural process is rendered moot. You provision the basic characteristics of the virtual systems you need to deliver services. And if they don't work well or properly, you change those characteristics. SOCCI has adopted this concept now, and is advancing it up until the time it needs to be completely redefined all over again.

Quoting from the newly revised framework:

Cloud computing puts new demands on the IT infrastructure and management thereof. It requires an abstract approach to the operational environment. A cloud computing provider cannot any longer tailor its environment for each subscriber. It means that instead of a physical device, cloud computing offers an abstraction of a server, file system, storage, network, database, etc. Moreover, increasing providers' profitability and maximizing the utilization of resources requires multi-tenancy, dynamic allocation of resources, and metering with charge-back.

At the same time, subscribers expect to see implementation of a utility model since they want to allocate resources on-demand and pay exactly for their usage while being able to sustain their operations, much like the electric bill. Hence, new infrastructure should be agile and elastic and create an illusion of infinite computing resources available on-demand. While SOI did not offer the whole spectrum of the characteristics desired, it became an enabler for what came to be known as Service-Oriented Cloud Computing Infrastructure (SOCCI). SOCCI can be defined as service-oriented, utility-based, manageable, scalable on-demand infrastructure that supports essential cloud characteristics, service, and deployment models. In other words, SOCCI describes the essentials for implementing and managing an Infrastructure as a Service (IaaS) environment.