Capacity Management is a process that extends across the Service Lifecycle. A key success factor in managing capacity is ensuring it is considered during the design stage. It is for this reason that the Capacity Management process is included in this publication. Capacity Management is supported initially in Service Strategy where the decisions and analysis of business requirements and customer outcomes influence the development of patterns of business activity (PBA), levels of service (LOS) and service level packages (SLPs). This provides the predictive and ongoing capacity indicators needed to align capacity to demand.
‘The goal of the Capacity Management process is to ensure that cost-justifiable IT capacity in all areas of IT always exists and is matched to the current and future agreed needs of the business, in a timely manner’.
The purpose of Capacity Management is to provide a point of focus and management for all capacity- and performance-related issues, relating to both services and resources.
The objectives of Capacity Management are to:
The Capacity Management process should be the focal point for all IT performance and capacity issues. Technology management functions such as Network Support, Server Support or Operation Management may carry out the bulk of the day-to-day operational duties, but will provide performance information to the Capacity Management process. The process should encompass all areas of technology, both hardware and software, for all IT technology components and environments. Capacity Management should also consider space planning and environmental systems capacity as well as certain aspects of human resources, but only where a lack of human resources could result in a breach of SLA or OLA targets, a delay in the end-to-end performance or service response time, or an inability to meet future commitments and plans (e.g. overnight data backups not completed in time because no operators were present to load tapes).
In general, human resource management is a line management responsibility, though the staffing of a Service Desk should use identical Capacity Management techniques. The scheduling of human resources, staffing levels, skill levels and capability levels should therefore be included within the scope of Capacity Management. The driving force for Capacity Management should be the business requirements of the organization and to plan the resources needed to provide service levels in line with SLAs and OLAs. Capacity Management needs to understand the total IT and business environments, including:
Understanding all of this will enable Capacity Management to ensure that all the current and future capacity and performance aspects of services are provided cost-effectively.
Capacity Management is also about understanding the potential for the delivery of new services. New technology needs to be understood and, if appropriate, used to innovate and deliver the services required by the customer. Capacity Management needs to recognize that the rate of technological change will probably increase and that new technology should be harnessed to ensure that the IT services continue to satisfy changing business expectations. A direct link to the Service Strategy and Service Portfolio is needed to ensure that emerging technologies are considered in future service planning.
The Capacity Management process should include:
Managing the capacity of large distributed IT infrastructures is a complex and demanding task, especially when the IT capacity and the financial investment required is ever-increasing. Therefore it makes even more sense to plan for growth. While the cost of the upgrade to an individual component in a distributed environment is usually less than the upgrade to a component in a mainframe environment, there are often many more components in the distributed environment that need to be upgraded. Also there could now be economies of scale, because the cost per individual component could be reduced when many components need to be purchased. Capacity Management should have input to the Service Portfolio and procurement process to ensure that the best deals with suppliers are negotiated.
Capacity Management provides the necessary information on current and planned resource utilization of individual components to enable organizations to decide, with confidence:
Many of the other processes are less effective if there is no input to them from the Capacity Management process. For example:
Capacity Management is one of the forward-looking processes that, when properly carried out, can forecast business events and impacts often before they happen. Good Capacity Management ensures that there are no surprises with regard to service and component design and performance.
Capacity Management has a close, two-way relationship with the Service Strategy and planning processes within an organization. On a regular basis, the long-term strategy of an organization is encapsulated in an update of the business plans. The Service Strategy will reflect the business plans and strategy, which are developed from the organization’s understanding of the external factors such as the competitive marketplace, economic outlook and legislation, and its internal capability in terms of manpower, delivery capability, etc. Often a shorter-term tactical plan, or business change plan is developed to implement the changes necessary in the short to medium term to progress the overall business plan and Service Strategy. Capacity Management needs to understand the short-, medium- and long-term plans of the business while providing information on the latest ideas, trends and technologies being developed by the suppliers of computing hardware and software.
The organization’s business plans drive the specific IT Service Strategy, the contents of which Capacity Management needs to be familiar with, and to which Capacity Management needs to have had significant and ongoing input.The right level of capacity at the right time is critical. Service Strategy plans will be helpful to capacity planning by identifying the timing for acquiring and implementing new technologies, hardware and software.