Quantifying incident impact in dollars and user-minutes turns "we had an outage" into a number leadership can actually weigh against the cost of preventing it, and the framework generalizes cleanly to per-tenant billing adjustments as well.
Structured elaboration
Required telemetry: a conversion-rate (or revenue-per-minute) BASELINE for normal operation, segmented by whatever dimensions matter (time of day, region, tenant), plus the observed degraded-period metrics (actual conversion rate or transaction volume during the incident) to compute the delta. The core formula: revenue loss≈(baseline revenue-per-minute−observed revenue-per-minute during incident)×incident duration in minutes, with user-minutes computed similarly as affected users×minutes affected (or an integral over a ramping partial-degradation curve, if impact wasn't uniform across the incident).
Worked example
If baseline revenue-per-minute is normally $2,000 and it drops to $600/minute during a 45-minute incident, the estimated loss is (2000−600)×45=$63,000. If the incident affected an estimated 8,000 concurrent users for the full 45 minutes, that's 8,000×45=360,000 user-minutes of degraded experience, a figure often reported alongside the dollar estimate since not every stakeholder finds a revenue number equally meaningful (e.g. for a free-tier or B2B-support-heavy incident, user-minutes may be the more persuasive figure).
Trade-offs and pitfalls
The baseline itself needs real care: comparing against "normal Tuesday afternoon" traffic when the incident happened during a known low-traffic period (or vice versa, a marketing-campaign traffic spike) will badly over- or under-estimate the loss, so the baseline should be matched to the SAME time-of-week/season as the incident, not a flat all-time average. This quantification also directly feeds two downstream processes that must be documented explicitly as assumptions, not silently assumed: per-tenant billing or credit adjustments (if this is a multi-tenant product with a financial SLA), which needs the SAME dollar-impact methodology applied at the individual tenant level rather than only in aggregate, and the post-incident review itself, where a credible dollar figure is often what actually secures follow-up engineering investment that a purely technical severity rating alone would not.
