ITIL Capacity Management is responsible for ensuring the capacity of IT Infrastructure matches the evolving demands of the business in the most cost-effective and timely manner. To enable ITIL Capacity Management to achieve its responsibilities it undertakes various activities including:
The monitoring of performance and throughput of IT Services and the supporting Infrastructure components
- Undertaking tuning activities, to make the most efficient use of existing resources
- Understanding current demands for IT resources and producing forecasts for future requirements
- Influencing the demand for resources and when appropriate in conjunction with ITIL Financial Management
- The production of a Capacity Plan, which enables the IT provider to deliver services of a quality defined in the SLA(s)
ITIL Capacity Management is essentially a balancing act of Cost against Capacity, and Supply against Demand. As a forward-looking process, ITIL Capacity Management if properly carried out, can forecast business impacts before they happen. In addition information is provided regarding current and planned resource utilization of individual components, assisting in determining which components to upgrade and when, together with how much the upgrade will cost.
For ITIL Capacity Management to meet its responsibilities it needs to understand the business requirements, the organization's operation and IT Infrastructure, to ensure the current and future Capacity and performance aspects of business requirements are provided cost-effectively. In addition ITIL Capacity Management understands, embraces and recommends new technology to support the services to business.
Benefits of ITIL Capacity Management
The benefits associated with ITIL Capacity Management take the form of increased efficiency, cost savings and reduced risks, including:
- The possibility to defer expenditure. With the pace of technological change, generally the later a purchase is left, the more Capacity is obtained for the money
- Matching the capacity to business need. Unnecessary spare Capacity is therefore not required to be maintained and cost savings result, ultimately existing Capacity is optimized
- Planned buying is always cheaper than panic buying
- Existing applications risks are minimized through the managing of resources and service performance
- Risks to new applications are reduced through application sizing. The introduction of new applications can have an adverse effect upon existing applications, the risks to those applications minimized
- The ITIL Capacity Management process interfaces into the Change Advisory Board (CAB) assisting to assess the impact of Changes upon existing Capacity, thus reducing the risk of Capacity Problems caused by Changes
- The reduction or elimination of the number of urgent Changes required to increase Capacity, achieved through effective Capacity planning
Possible Problems
The following provide examples of some of the possible problems that may be encountered, including:
- Customer expectations often exceed technical capabilities. It is essential that expectations for new applications be managed from the outset. ITIL Capacity Management discuss with the Customers the technical feasibility and cost implications of meeting over-ambitious requirements - this forms part of the application sizing activity. Improvements are made through regular tuning, which may not be significant
- Manufacturer's quoted performance figures are often not achievable within a production environment. Where possible, performance figures should be verified through reference to site visits or by simulation testing where appropriate, prior to the purchase taking place
- Time-to-market demands are ever decreasing, resulting in business planning cycles being shorter. Even the best business planning function cannot always accurately predict demand. The Internet is a prime example where consumers literally 'at click of a button' are lost forever as they go elsewhere to receive a service, never to return to a temporarily unavailable or slow site. It is not possible to provide consistently high quality service levels, cost effectively, without timely and accurate business planning information being made available. This problem can be helped if the ITIL Capacity Management process understands the business and is able to talk to the Customer in their language
- ITIL Capacity Management is often considered a requirement within the host environment. Network or client environments are not included as part of the ITIL Capacity Management process
- Whether careful consideration is given to the level of monitoring to be undertaken, ranging from the Business impact of a component failure, the volatility of utilization, the ability to automate monitoring and reporting
Costs
The costs associated with implementing and sustaining ITIL Capacity Management include:
- The procurement of hardware and software tools, including monitoring, modelling and reporting
- Project management
- Staff costs including the recruitment, training and consultancy
- Accommodation
- Annual maintenance and any required upgrades of hardware and software tools
- On-going staff costs, including salaries, training and possibly consultancy as required
- Recurring accommodation costs
ITIL Capacity Management responsibilities may be distributed geographically and functionally within organization. Additional costs are incurred for central co-ordination and reporting of Capacity information.