Error Budgets: Quantifying Acceptable Failure¶

If your SLO is 99.9%, your error budget is 0.1% - a spendable resource that enables velocity when under budget and forces reliability focus when depleted.

Tension Addressed¶

Availability vs. Reliability - error budgets operationalize the trade-off

Recognizable As¶

Any resource that permits risk-taking when plentiful and demands caution when scarce; feature flags and rollout velocity decisions; "how much runway do we have"

Canonical Sources¶

Google SRE Book, Chapter 3 (2016); "Implementing Service Level Objectives" (Hidalgo, 2020)

Transfers To¶

Financial risk management (risk budgets), Project management (contingency buffers), Safety engineering (acceptable risk thresholds)

Error budgets transform reliability from "always be more reliable" to "be reliable enough." When budget is available, teams can ship riskier changes; when depleted, stability work takes priority.