Your company wants to track costs per department. Each department has its own project. You need to set up a budget alert in the billing account for each project. What is the most efficient approach?
Creating one budget per project and setting the 'Scoped to' field to that project is the correct, efficient approach. In the Google Cloud console, budgets are created at the billing account level but can be scoped to a specific project, which allows the budget amount and alert thresholds to apply exclusively to that project's costs. This directly enables per-department tracking if each department maps to a project, and it provides native budget alert notifications, exactly as required.
Why this answer
In GCP, a Cloud Billing budget can be scoped to a specific project using the 'Scoped to' field, allowing you to create one budget per project directly from the billing account without needing to enable billing separately or export data. This is the most efficient native approach because budgets support project-level scoping out of the box. It avoids the overhead of BigQuery export and custom monitoring setup.
Exam trap
ACE often tests the misconception that a single billing-account budget with labels is equivalent to per-project budgets, when in fact scoped budgets give cleaner per-project alerting.
How to eliminate wrong answers
Option A is wrong because Billing Export to BigQuery plus Cloud Monitoring is a heavier, custom-built solution requiring data pipeline setup and alert configuration, not the most efficient native approach. Option C is wrong because enabling billing per project is a prerequisite, not a budgeting mechanism, and it does not create budget alerts. Option D is wrong because a single billing-account-wide budget with labels cannot enforce per-project thresholds or send project-specific alerts as cleanly as scoped budgets.