Cloud computing provides resources on demand, i.e. when the consumer wants it. This is made possible by self-service and automation. Self-service means that the consumer performs all the actions needed to acquire the service herself, instead of going through an IT department, for example. The consumer’s request is then automatically processed by the cloud infrastructure, without human intervention on the provider’s side.

To make this possible, a cloud provider must obviously have the infrastructure in place to automatically handle consumers’ requests. Most likely, this infrastructure will be virtualized, so different consumers can use the same pooled hardware.

On-demand self-service computing implies a high level of planning. For instance, a cloud consumer can request a new virtual machine at any time, and expects to have it working in a couple of minutes. The underlying hardware, however, might take 90 days to get delivered to the provider. It is therefore necessary to monitor trends in resource usage and plan for future situations well in advance.

Simple User Interfaces

The cloud provider can’t assume much specialized knowledge on the consumer’s part. In a traditional enterprise IT setting, IT specialists process requests from business. They know, for instance, how much RAM is going to be needed for a given use case. No such knowledge can be assumed on the part of a cloud service consumer. This means that the user interface (UI) to the cloud service must not ask such questions. Instead, the cloud provider must put a lot of thought into providing an understandable UI with good defaults, and translate that into technical details, like the IT specialist used to do.

Policies

The high level of automation required for operating a cloud means that there is no opportunity for humans to thoroughly inspect the specifics of a given situation and make an informed decision for a request based on context. Instead, the thinking through of possibilities has to happen well in advance, and then has to be formalized in the form of a limited set of policies that can be automatically executed by the cloud infrastructure.