ITIL Capacity Management

What is it?

Capacity Management is one of five components in the ITIL Service Delivery area. The work is proactive rather than reactive in nature and is responsible for ensuring that business needs and service definitions are fulfilled using a minimum of computing resources.

Capacity Management activities include:

• Monitoring, analyzing, tuning, and implementing necessary changes in resource utilization
• Managing demand for computing resources, which requires an understanding of business priorities
• Modeling to simulate infrastructure performance and understand future resource needs
• Application sizing to ensure required service levels can be met
• Storing capacity management data
• Producing a capacity plan that documents current utilization and forecasted requirements, as well as support costs for new applications or releases
• Building the annual infrastructure growth plan with input from other teams

 

Why should I implement Capacity Management?

To ensure that all current and future capacity and performance aspects of the IT infrastructure are provided to meet business requirements at acceptable cost.
Immediate and long term benefits include lower costs, more consistent levels of service and improved service quality.
Processes allow you to:

• Get more out of existing IT resources and improve IT cost per service unit positions
• Fine tune applications and infrastructure components to improve performance, reduce consumption, and delay upgrades
• Eliminate redundant work and ensure consistent reporting
• Efficiently provision capacity
• Provide timely capacity and related cost information for more informed business decisions
• Provide more complete input to TCO of proposed new and/or major IT-related upgrades or initiatives
• Project consumption at future growth levels and uncover bottlenecks with sufficient warning to correct before business services are adversely affected Capacity management teams have close ties to ITIL Service Level Management and Financial Management areas. Through Capacity Management processes, more thorough service level and associated financial information is available to the business, permitting business leaders to make more informed decisions.

Basic concepts

• Performance Management - measuring, monitoring and tuning the performance of IT infrastructure components for optimum performance
• Application Sizing - determining the hardware or network capacity needed to support new or modified services and the predicted future workload
• Modeling - using analytical, simulation or trending models to determine the capacity requirements of services and determining  the  best capacity solutions. Modeling allows various scenarios to be analyzed and the what-if question address.
• Workload management - dealing with understanding what the various business drivers are doing, and what resources they require - a foundational component of modeling, but also stands alone.
• Capacity Planning - developing a Capacity Plan, based on a Capacity Management Database, analyzing the current situation and predicting the future use of the IT infrastructure and the resources needed to meet the expected demand for IT services (preferably using scenarios).

Process

Process Goal

• To determine the right cost, justification, and capacity of IT resources such that Service Levels agreed with the business are achieved at the right time
• To understand the business requirements, current operations and IT infrastructure to ensure that current and future capacity and performance aspects of the business are provided cost-effectively
• ITIL-aligned Capacity management policies, processes and procedures
• Dedicated Capacity Management Process Owner
• Business Capacity Management to forecast capacity needs based on business events
• Service Capacity Management to ensure capacity levels support established service level targets
• Resource Capacity Management to ensure capacity levels are provided for at the individual IT device level
• Actions to ensure appropriate levels of capacity have been built into new IT Solutions
• Periodic and ongoing forecasting for capacity needs based on both business and technical input
• Ongoing monitoring and analysis of current performance to ensure appropriate levels of capacity have been provided and resources are optimally tuned

Benefits

• Increased efficiency and cost savings
• Economic Provision of Services. Capacity is matched to business need and unnecessary spare capacity is not being purchased or maintained
• Planned buying is cheaper than panic buying
• Allows an organization to take advantage of economies of scale and market conditions
• Reduced risk of performance problems and failure
• Workload forecasts on time
• Increased ability to monitor performance
• Reduction in the over capacity of IT
• Percentage reduction in number of capacity incidents

Roles

• The Capacity Manager
• The Capacity Manager ensures the fulfillment of the business requirements, in that he makes the necessary IT Capacities available (Hardware, Software, Personnel).
• To achieve this he creates forecasts of the future demand, from which planning for the necessary future capacities (the Capacity Plan) can be derived.

Tool Requirement Considerations

• Tools – Modeling software, model generators, resource utilization software, performance surveillance software, workload performance monitors, financial planning software (used by Financial Management, FM), charging software (used by FM), business forecasting software, Capacity Plan, capacity planning database, application sizing software
• Techniques – Modeling, Queuing theory, Sizing (Application), Rule of thumb, Trending

Possible costs

• Purchase of tools must always be justified in terms of savings they will generate
• Planned purchasing should deliver economies of scale
• Possibly buy in skills rather than develop and maintain them in-house
• Understand the true cost of under-utilized resources

Relations whit others process

Service Support

	Problem	Incident	Configuration	Change	Release
Input	Capacity problems and Known Errors	Capacity and performance related incidents	Technical, service, utilization, financial, and business data retrieved from database monitored by Configuration Management	Additional capacity requirements
Output	Significant Trends in capacity problems	Resolved capacity incidents	Technical, service, utilization, financial, and business data retrieved from database monitored by Configuration Management	Impact of changes upon capacity needs	Planning data and technical expertise supporting distribution strategy

Table 1 - Relations whit other process of Service Support

 

Service Delivery

	Availability	SLM
Input	Capacity Requirements
Output		Verification that performance and capacity target for new requirements can be achieved Suggestions for OLAs

Table 2 - Relations whit other process of Service Delivery

 

Figure 1-Capacity Management Activities

 

Sub-Processes

Capacity management is made up of three sub-processes:

• Business capacity management (BCM)
• Service capacity management (SCM)
• Resource capacity management (RCM)

 

Business Capacity Management:

Goals:

• Understand current and future needs of the business of IT service.
• Ensure that the taking of the necessary capacity is planned and implemented in time.
• Working with the Service Level Management in establishing performance targets for SLAs.
• specify, acquire or improve configurations to meet the requirements.

Service Capacity Management:

Goals:
• Identify and understand the patterns of work and use of resources for IT Services.
• ensure that the goals of performance for the services defined by the Business Management Capacity are met.
• Monitor and report the performance of services, with relation to the targets set out in SLAs and SLRs.
• pro-actively prevent problems by identifying the worrying trends and triggering corrective action.

Resource Capacity Management:

Goals:
• Identify and understand the available capacity and use current and planned components of the infrastructure for IT.
• Ensure the optimum use of existing hardware and software, to meet the goals of performance.
• Estimate the effects of changes (RFC and Changes) in the performance of services and consequently generating initiatives for planning and budgeting for upgrades.
• Understanding of how new technologies can be used to improve the current form of provision of services.
• Collaborates with Availability Management in identifying vulnerabilities in infrastructure (CFIA using, for example) and recommend improvements, based on cost-benefit analysis.

These sub-processes all share a common set of activities that are applied from different perspectives. They include the following:

• Modeling
• Service monitoring
• Performance management
• Demand management
• Workload management
• Analysis
• Change initiation
• Optimization
• Trend analysis

From these processes come the results of capacity management, these being the capacity plan itself, forecasts, tuning data and Service Level Management guidelines.

All the information obtained in these activities, and that generated by Capacity Management using that information, is stored and recorded in the Capacity Database (CDB).

Monitoring

The main objective is to ensure that the performance of the IT infrastructure matches the requirements of the SLAs.

As well as technical aspects, monitoring needs to include details of licences and other administrative information.

Analysis and Evaluation

The data collected needs to be analysed to assess whether corrective action needs to be taken, such as requesting an increase in capacity or better Demand Management.

Optimisation and changes

If it is decided that capacity needs to be increased, an RFC will be raised and sent to Change Management to set in train the whole process involved in implementing the change. Capacity Management will lend its support throughout the process and it will be jointly responsible, together with Change Management and Release Management for ensuring that the change requested meets the envisaged objectives.

In the case where a simple rationalisation of demand will be enough to resolve the deficiencies or noncompliances with SLAs, Capacity Management itself will be responsible for managing this sub-process.

Capacity Database

The CDB must cover all the business, financial, technical and service information received and generated by Capacity Management in relation to the capacity of the infrastructure and its elements.

Ideally, the CDB must be interrelated with the CMDB so that the CMDB is able to give a complete image of the systems and applications and includes all the information about their capacity. However, this does not mean that the two databases cannot be "physically independent".

Critical Success Factors (CSFs)

The Critical Success Factors (CSFs) are:

• Providing Accurate IT Capacity Forecasts
• Providing Appropriate IT Capacity To Meet Business Needs

Key Activities

The key activities for this process are:

• Perform demand management for business, service and resource capacity activities
• Provide application sizing for business, service and resource capacity activities
• Provide capacity plans for business, service and resource capacity activities
• Perform capacity monitoring, analysis and tuning activities
• Implement capacity-related changes
• Control storage of capacity data for capacity activities
• Provide management information about Capacity Management quality and operations.

Key Performance Indicators (KPIs)

The success of Capacity Management depends on a number of key indicators, including:

• Correct forecasting of capacity needs.
• Reducing costs associated with capacity.
• Higher levels of security and availability.
• Greater user and customer satisfaction.
• Compliance with the SLAs

Examples of Key Process Performance Indicators (KPIs) are shown in the list below. Each one is mapped to a Critical Success Factor (CSF).

Providing Accurate IT Forecasts

• Total dollars in unplanned capacity expenditures
• Total dollars in unused capacity expenditures
• Percent of capacity forecasts that were accurate
• Number of inaccurate business forecast inputs provided

Providing Appropriate IT Capacity To Meet Business Needs

• Number of incidents related to capacity/performance issues
• Number of SLA performance targets missed due to capacity

 

Documents

The documentation drawn up must include information about:

• The use of resources.
• Deviations of the real capacity from that planned.
• Analysis of trends in the use of capacity.
• Metrics established for capacity analysis and performance monitoring.
• Impact on quality of service, availability and other IT processes.

According to Figure 1, capacity management is related whit 3 Documents:

• Capacity Plan
• Capacity and Performance Reports and Data
• Forecasts
• Exceptions Report (SLM orResource Utilization)

Capacity Plan

• It documents the current situation of use of resources and performance of services.
• Based on the strategy and plans of the business, provides resources for future requirements of IT.
• It must be aligned with the cycle of planning and business finalized in time of negotiations of the budget.
• It should be published annually, but should be updated and republished to take into account changes supervening and incorporate new results of analysis estimates.

Modelling and Benchmarking

The more complex the IT infrastructure, the more difficult it is to forecast future capacity needs. This makes it essential to use models and simulations of possible scenarios for future developments so as to ensure hardware and applications are properly scalable.

The level of detail to which this modelling is taken will depend on several factors:

• Costs associated with the increase in capacity.
• Costs inherent in the process of modelling and simulation itself.
• Scope of the envisaged capacity increases.
• The "criticality" of the systems involved.

Weighing up these factors we can opt for:

• A simple analysis of trends which allows the process load on the IT infrastructure to be assessed and the current capacity scaled accordingly.
• modelling and simulating various different scenarios in order to make load forecasts and predict the response of the IT infrastructure.
• Benchmarking real prototypes to ensure the capacity and performance of the future infrastructure.

 

Document Basics Contents

Title	Description
Consignees	People or Process to whom the plan is intended
Date of last CP	Date of the last CP(Capacity Plan)
Date	Date of the current CP
Date of the revision	Deadline to carry out the next CP (max. 1 year)
CI covered	List the CI covered in the CP
Current state of CI	For each CI list its current state, as well as the use and capacity
Forecast Report	This report contains forecasts for the use of CI
Amendments and Proposed Recommendations	RFC's proposed to change management, to support the projected capacity

Capacity and Performance Reports and Data

Title	Description
Consignees	The recipient of the report
Date	Reports date
CIs	CIs covered by the report
KPIs	Key Performance Indicators for each CIs
Business Impact	Business Impact

Forecasts
   

Title	Description
Current Capacity	It describes the capacity of ICs
Demand variation	It represents the pattern of use of each ICs
Forecasts by Demand Variation	Determina as previsões para cada Variação na Procura
Date	Report Date
CIs	CIs covered by the report

Exceptions Report

Title	Description
Consignee Process	Consignee Process of Service Management
CIs	CIs covered
Details of the Exception	It presents the details known about the exception
Recommendations	Recommendations for resolution