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Unavailability analysis



All events and incidents causing unavailability of services and components should be investigated, with remedial actions being implemented within either the Availability Plan or the overall SIP. Trends should be produced from this analysis to direct and focus activities such as Service Failure Analysis (SFA) to those areas causing the most impact or disruption to the business and the users.

The overall costs of an IT service are influenced by the levels of availability required and the investments required in technology and services provided by the IT support organization to meet this requirement. Availability certainly does not come for free. However, it is important to reflect that the unavailability of IT also has a cost, therefore unavailability isn’t free either. For highly critical business processes and VBFs, it is necessary to consider not only the cost of providing the service, but also the costs that are incurred from failure. The optimum balance to strike is the cost of the availability solution weighed against the costs of unavailability.

Before any SLR is accepted, and ultimately the SLR or SLA is negotiated and agreed between the business and the IT organization, it is essential that the availability requirements of the business are analysed to assess if/how the IT service can deliver the required levels of availability. This applies not only to new IT services that are being introduced, but also to any requested changes to the availability requirements of existing IT services.

The cost of an IT failure could simply be expressed as the number of business or IT transactions impacted, either as an actual figure (derived from instrumentation) or based on an estimation. When measured against the VBFs that support the business operation, this can provide an obvious indication of the consequence of failure. The advantage of this approach is the relative ease of obtaining the impact data and the lack of any complex calculations. It also becomes a ‘value’ that is understood by both the business and IT organization. This can be the stimulus for identifying improvement opportunities and can become a key metric in monitoring the availability of IT services.

The major disadvantage of this approach is that it offers no obvious monetary value that would be needed to justify any significant financial investment decisions for improving availability. Where significant financial investment decisions are required, it is better to express the cost of failure arising from service, system, application or function loss to the business as a monetary ‘value’.



The monetary value can be calculated as a combination of the tangible costs associated with failure, but can also include a number of intangible costs. The monetary value should also reflect the cost impact to the whole organization, i.e. the business and IT organization.

Tangible costs can include:

  • Lost user productivity
  • Lost IT staff productivity
  • Lost revenue
  • Overtime payments
  • Wasted goods and material
  • Imposed fines or penalty payments.

These costs are often well understood by the finance area of the business and IT organization, and in relative terms are easier to obtain and aggregate than the intangible costs associated with an IT failure.

Intangible costs can include:

  • Loss of customers
  • Loss of customer goodwill (customer dissatisfaction)
  • Loss of business opportunity (to sell, gain new customers or revenue, etc.)
  • Damage to business reputation
  • Loss of confidence in IT service provider
  • Damage to staff morale.

It is important not simply to dismiss the intangible costs (and the potential consequences) on the grounds that they may be difficult to measure. The overall unavailability of service, the total tangible cost and the total intangible costs arising from service unavailability are all key metrics in the measurement of the effectiveness of the Availability Management process.





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