It does this by grouping computing equipment into pools of resources that can be rapidly or automatically reconfigured to respond to changing work requirements. Utility computing goes by many other names, including "adaptive enterprise" at Hewlett-Packard, "e-business on demand" at IBM and "dynamic" or "organic" information technology at analyst firms.
For businesses, utility computing can mean big savings, since they no longer need to maintain some or all of their own hardware and software. The utility computing providers worry about building and maintaining infrastructure, updating software releases and negotiating licensing terms with software makers.
That's the vision. But today's utility computing closely resembles the standard outsourced services that have existed for years. To get closer to the vision, sellers and businesses say, better standards and more well-defined pricing plans need to be created.
At the heart of utility computing is management software that detects workload requirements and controls which resources are allocated to specific tasks. Several key components of the software are also involved: some that can meter computer system consumption; some that can "provision" software so that a server switches from one job to another; some that can "virtualize" hardware resources so that tasks can be easily moved from one computer to another; and some that can ensure that service contracts are being met.
While software companies such as Microsoft, Veritas Software and Computer Associates International are involved, hardware also figures in the equation. Indeed, much of today's utility computing work began at server makers IBM, HP and Sun Microsystems. These companies have various mechanisms to add more computing capacity to a system and in some cases temporarily rent more power. Among these mechanisms are clustered hardware servers and "grid" computing, which links groups of servers to harness processing power.
Utility computing is still young, and customers have only begun evaluating its ideas. There has been no shortage of fanfare about the utility computing visions, and many advocates today have begun showing that they have concrete products or services to offer.