Measure AI cost per useful task, not only cost per token
Connect model, orchestration, retrieval, storage, review, retry, and support costs to a completed task the venture values.
Direct answer
Tokens, compute time, and API calls are billing units. A venture needs a decision unit such as cost per reviewed support draft, accepted document extraction, or completed workflow. Count retries and human review in the denominator and numerator.
Decision sequence
- Define the useful task and the acceptance rule that determines whether it completed.
- Measure every paid and internal component needed for the task, including failed attempts and review.
- Calculate low, expected, and peak monthly ranges rather than one precise forecast.
- Compare actual cost and useful completion rate after a bounded pilot.
Evidence to keep
- A billing-unit inventory.
- A useful-task acceptance rule.
- Retry, rejection, and review rates.
- An owner for budget alerts and model changes.
Sources and interpretation boundaries
Decision boundary
This guide is an original educational synthesis. It does not inspect your workload, validate a contract, test a provider, certify security, recommend an investment, or promise cost, performance, funding, revenue, savings, or growth.