Best KPI for Measuring Uninterrupted IT Service Delivery?

CRISC By islever Editorial Last updated

Short answer

B Mean time between failures (MTBF)

Question

Which of the following is the BEST key performance indicator (KPI) to measure the ability to deliver uninterrupted IT services?
  1. Mean time to recover (MTTR)
  2. Mean time between failures (MTBF) Correct Answer
  3. Planned downtime
  4. Unplanned downtime

Key Takeaways

The question evaluates knowledge of availability versus reliability metrics, with the common trap being confusing MTBF (failure frequency) with MTTR (recovery speed) or focusing narrowly on unplanned downtime instead of the proactive reliability indicator.

This CRISC question tests your understanding of IT service reliability metrics, specifically focusing on Mean Time Between Failures (MTBF). Community experts consistently confirm that MTBF is the optimal KPI for measuring an organization’s capacity to deliver uninterrupted IT services.

Common mistake: Option D (Unplanned downtime) is frequently chosen because it seems to directly reflect service interruptions; however, it is a reactive lagging indicator rather than a comprehensive measure of systemic reliability and continuous delivery capability.

Expert Analysis

Why the Answer Is Correct

MTBF quantifies the average time elapsed between inherent failures of a system during normal operation. A higher MTBF directly correlates with greater system stability and a stronger ability to maintain continuous service delivery without interruption. In IT risk and operations frameworks, it serves as the primary leading indicator of reliability.

Why the Other Options Are Wrong

MTTR measures recovery speed post-failure, which impacts availability but does not directly gauge the baseline capability to prevent interruptions. Planned downtime is scheduled maintenance and does not reflect organic service continuity. Unplanned downtime is a reactive metric that records past failures rather than proactively measuring the system’s inherent resilience and uninterrupted delivery potential.

Community Comment Notes

Multiple users highlighted that MTBF directly supports uninterrupted service by indicating long operational periods without failure. Experts emphasized that while unplanned downtime is relevant, MTBF offers a more comprehensive and standardized measure of reliability. Consensus strongly aligns with official ISACA guidance on availability KPIs.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

When evaluating availability and reliability KPIs on the CRISC exam, distinguish between leading indicators that predict future performance and lagging indicators that record past events. Always select the metric that best reflects proactive system resilience and continuous operational capability rather than reactive recovery or historical fault counts.

Community Votes

B
67%
D
33%

67% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 5 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 5

  1. Joloms 👍 1
    he best key performance indicator (KPI) to measure the ability to deliver uninterrupted IT services is D. Unplanned downtime. Unplanned downtime refers to the time when IT services are unavailable due to unexpected events such as system failures, software glitches, or hardware malfunctions. This metric directly measures the organization's capability to maintain continuous operations without disruptions. Minimizing unplanned downtime is crucial for ensuring the reliability and availability of IT services, which is essential for business continuity and customer satisfaction. While MTTR (Mean Time to Recover) and MTBF (Mean Time Between Failures) are also relevant metrics in the context of IT service delivery, they focus on different aspects. MTTR measures the average time taken to restore services after an outage, while MTBF
  2. Sara98 👍 1 Answered B
    While the other options are also relevant, MTBF provides the most direct and comprehensive measure of the ability to deliver uninterrupted IT services.
  3. faed87a 👍 1 Answered B
    A high MTBF indicates that systems run for long periods without failing, which directly supports uninterrupted service.
  4. Promz 👍 1
    Similar to 504, MTBF right answer
  5. K5000ism 👍 1 Answered D
    D. Unplanned downtime

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