IBM has begun providing the infrastructure to meet its e-business on-demand strategy first announced last autumn, with products and services for accessing IT capacity as needed.

The company has extended the 'pay-as-you-grow' approach to buying systems and services and the option of paying monthly, varying order content along the way.

"To be efficient and flexible enterprises need to use IT resources on the basis of their business model, not on the basis of physical need," said Michel Teyssedre, IBM vice president of strategic business development for eServer sales.

"That is where the value is."

But companies need to plug their business processes into an on-demand infrastructure, he added.

IBM Open Infrastructure Offering allows enterprise customers to acquire all or part of a planned IT infrastructure, plus services, for a single monthly price. Flexibility is built into the contract to accommodate variations as needed.

Standby Capacity On Demand, for IBM's blade servers and storage systems, offers a fully configured system for a price that covers only the capacity used. Extra capacity is then turned on and paid for as needed over the following six months.

This builds on capacity on-demand already provided for IBM z, x and pSeries systems. IBM iSeries also provides temporary capacity on-demand, where users pay for the amount used, which can move up and down. Teyssedre said this would come to other servers in the near future.

"For on-demand IBM is streets ahead of others," said Tim Jennings, research director at analyst Butler Group.

"It has to span across such a lot of different things it is not easy for other companies to react quickly. It is not just the technical issue. It needs the services."

But it was still early days and commercial IT managers may not yet see much benefit, Jennings added.

Among infrastructure products released is IBM Web Server Provisioning, a set of self-managing facilities to enable automatic switching to, or addition of, another server for immediate capacity increase.

This application, packaged with IBM Tivoli infrastructure management software, is aimed at reducing the IT department burden by automatically configuring new server software and hardware.

An early user is MasterCard, which authorises millions of card transactions daily. On-demand capabilities are aimed at quickly reacting to spikes in demand.

IBM WebSphere has become the first application server to include grid middleware, used for virtualising and aggregating computing power for applications to use as required.

SAN Integration Server (previously known as StorageTank) is promised for December.