Capacity Management
ITIL® defines Capacity Management as:
…[processes] to ensure that cost justifiable IT Capacity always exists and that it is matched to the current and future identified needs of the business.
While many other Disciplines are focused squarely on the present, Capacity Management stands apart for two reasons. First, like quality, capacity should be considered at the outset, when requirements are being gathered, so it can be built into the service rather than added later. Second, Capacity Management should contribute to the Business Plan, with the Capacity Plan mirroring production forecasts in response to anticipated market demand. Both of these points require the ability to predict based on anticipated need and therefore they set Capacity Management apart from Disciplines that react primarily to input from users.
To accommodate the need to be both forward-looking and yet able to react to current capacity issues, such as those generated in response to an incident and highlighted by Problem Management, Capacity Management is actually composed of three sets of sub-processes: Service Capacity Management, Business Capacity Management, and Resource Capacity Management. As illustrated below, these sub-processes function together by focusing on a particular aspect within the context of a specific timeframe. Service Capacity is focused on the live, production environment and whether the targets within the Service Level Agreements (SLAs) are being met; context is the present. Business Capacity is focused on evaluating, planning, and implementing IT services to meet anticipated demand; context is the future. Resource Capacity is focused on ensuring the requirements of both the Service and Business Capacity sub-processes are met and therefore it must be able to satisfy both present and future needs. more »
