Anticlue

ITIL: Capacity Management Activities and Methodology

Capacity management is the practice of considering future capacity requirements for the current and yet to be implemented IT services. The purpose of capacity management is to ensure sufficient capacity exists to support new services and solutions considering the advances in new technology. Employing a capacity management process helps to ensure there is adequate funding so that new capacity can implemented when needed.

Service capacity management monitors and controls the performance of the customer’s IT services through examining relevant data. Resource capacity management monitors the performance of components within the IT infrastructure. The activities of service capacity management and resource capacity management are:

• Demand management – Demand management is the practice of transferring and transition demand in order to prevent an infrastructure component from becoming overloaded. Demand management reviews capacity requirements from both a long term and short term perspective.
• Monitoring - Monitoring the infrastructure components is a way to measure and assure that the agreed-upon service levels can be achieved. Examples of resources that should be monitored are central processing unit (CPU) utilization, disk utilization, network utilization, and the number of concurrent licenses in use.
  
• Analysis - Trend analysis is utilized as a measure to forecast future utilization needs. An analysis of current systems and components may initiate efficiency improvements or the acquisition of additional IT components.
• Tuning - Tuning helps better utilize system resources or improve the performance of a particular service by identifying steps to take which will optimize the system for current or anticipated workload.
• Implementation - Implementation is the process of implementing the changed or new capacity which was identified during the monitoring, analysis, and tuning activities.

Business Capacity management is the process which predicts future business needs based on the analysis of the data. The activities associated with business capacity management are:

• Modeling – Modeling is a tool which helps to predict the current and future behavior of the infrastructure and to determine capacity requirements based on a given volume and variety of work.
• Application sizing – Application sizing evaluates the necessary resources to run new or changed applications. The resulting predictions include information about expected performance levels, necessary hardware, and costs.
• Capacity planning - Capacity planning analyzes future needs.

The Capacity Database (CDB) contains the relevant Capacity Management technical and business information. When populating the CDB, capacity and performance data from the necessary system components should be added. Data from components that make up the service can then be combined for analysis and provision of technical and management reporting.