Availability & Capacity Management

The purpose of the availability management practice is to ensure that services deliver agreed levels of availability to meet the needs of customers and users. Ensuring services are available when and where agreed is at the core of service operation and one of the key metrics for any service provider. It can often shape the perception of the business as to the quality and stability of services being provided. The clarity in what availability of services and components of those services means business terms and the relevant targets should be defined and documented in all service level agreements. Availability must also be clarified as ‘service’ availability and measured accordingly – i.e. the entire value stream or ‘bundle’ of components that go to make up the service, not simply one or more individual system components. “Availability” – the ability of an IT service or other configuration item to perform its agreed function when required.

The purpose of the capacity and performance management practice is to ensure that services achieve agreed and expected performance, satisfying current and future demand in a cost-effective way. Without due consideration given to the capacity and performance of every component of s service, organizations run this risk of service failure and extended downtime. Given this level of criticality, organizations often look to automated methods of monitoring and management performance, with related automated actions (for example load balancers in a server cluster). As with availability management, this practice will interact with many others but should have formal policies for engagement with change management, release management, deployment management, service validation and testing, infrastructure and platform, Software development and management, event management, and configuration management.