What is the main reason a team writes an error budget policy?
Show answer and explanation
Answer: B
An error budget policy turns the error budget into an agreed decision rule. It states in advance what happens at different levels of consumption, such as slowing releases after half the budget is spent and freezing features once it is gone. Because product and SRE agree on these rules before an incident, the trade-off between velocity and reliability is made by policy instead of by argument during a crisis. It is not a limit on incident count, a cost forecast, or a staffing plan.
Why the other options are wrong
- A. Incident counts are not what the policy limits. Declaring incidents is part of normal operations, and the policy instead tracks how much unreliability the service has spent against its objective.
- C. Cloud spend is a finance concern and is not the purpose of an error budget. The budget measures unreliability relative to an SLO, so a cost forecast would not drive its decisions.
- D. Staffing rotations are set through on-call planning, not through the error budget policy. The budget governs release decisions and reliability priorities, not how many engineers are assigned to the pager.