The IT community is now strongly focusing on the impact of cloud computing on their businesses. This can largely be explained by the fact that the rapid growth in the use of cloud services in recent years massively disrupts traditional IT delivery models.
But much confusion remains regarding the nature, scope and definition of cloud computing. The situation is becoming cloudier (excuse the pun), as major IT suppliers start to re-brand existing offerings as "private clouds". Attributes of cloud computing typically include scalability, elasticity, multi-tenancy, payment models that are linked to usage, resources delivered from virtualized environments and the provision of all support and management tasks by a cloud services provider.
However, the emergence of the marketing term, "private cloud" challenges common definitions of cloud computing and creates confusion. It is a term that is commonly used by those with vested interests in existing computing paradigms.
In my view, the use of private clouds is not cloud computing, since key attributes of cloud computing include the use of computing resources that reside outside of the enterprise and that are delivered to multiple customers (multi-tenancy) by a third party (cloud services provider). Private clouds deliver IT resources from within the corporate firewall and to one customer. To me, the term private cloud is a misleading way of describing hosted services. In fact, it is an oxymoron. It is a term that is used by providers of hosted services to hold onto lucrative contracts and prevent the loss of customers to companies that provide public cloud services.
Companies that offer services from the public cloud such as Salesforce.com are undermining traditional on-premise business models. The business case for sourcing resources from public clouds will soon be indisputable. In the next few years, business units and IT managers will need to provide business cases for not using public clouds and for keeping resources on-premise.
Services that share the attributes of public cloud computing, have, of course been with us for many years. For example, the application service provider (ASP) model of computing was expected to deliver services from the Internet to multiple clients. The ASP model did not mature for a variety of reasons.