Capacity

According to ITIL, Capacity can be defined as "The maximum throughput that a configuration item or IT service can deliver. For some types of CIs, the capacity may be the size or the volume - for example, a disk drive".

Capacity Management can be defined as "The process responsible for ensuring that IT service capabilities and IT infrastructure are able to meet agreed capacity and performance requirements in a timely and cost-effective manner".

Capacity Management considers all the resources needed to deliver an IT service and addresses the attendance of current and future capacity and performance needs of the business.