The plain-English version
A measured signal representing some aspect of service behavior.
Why it matters
It gives reliability discussions a precise measurement definition and observation window. Ratio-based indicators also need an explicit numerator and denominator.
Let’s make it click
The proportion of valid checkout attempts completed successfully is one possible indicator.
Vibe Bro’s heads-up
CPU usage alone may not describe whether users can complete the task; choose a signal connected to actual service behavior.
The docs behind it
Documentation links checked .
Editorial review · October 28, 2026
Corrected: SLIs can be latency percentiles, throughput, or other measures as well as success ratios; an explicit numerator and denominator is not the universal definition.