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Suppose a principal engineer spends $1,200 on AI usage and closes a revenue-blocking defect in one day instead of two weeks. Finance sees the $1,200. The thirteen days recovered are harder to see.
Now suppose another engineer spends $180 and delivers nothing the business accepts. A per-engineer token cap makes the second engineer look cheaper because it measures the invoice instead of the outcome.
That is the mistake.
Budget the work, not the person.
Use one decision rule:
Net gain = net value created + cash costs actually avoided − all added AI cost
Net value means contribution margin, cash flow, or an avoided loss. It does not automatically mean gross revenue. Added AI cost means the full incremental cost of model usage, infrastructure, review, rework, and support.
Released employee capacity is not cash savings. Count what the next work returns only after you measure it, and do not count the same benefit twice.
Use one illustrative scenario. Replace these assumptions with your actual numbers.
Four engineers need ten weeks to deliver one roadmap item. At a fully loaded cost of $3,750 per engineer per week, the labor assigned to the item is $150,000.
Suppose $30,000 of all-in added AI cost cuts delivery from ten weeks to five without changing scope, quality, security, or operational risk. The labor assigned to the item falls to $75,000, but the company may still pay the same salaries.
Now assume shipping five weeks earlier produces $20,000 per week in net value. Earlier delivery is worth $100,000.
Apply the rule:
$100,000 earlier net value − $30,000 added AI cost = $70,000 net gain
That is the defensible base case.
If the company also avoids $75,000 of actual labor expense, the gain becomes $145,000. If the same employees move to the next priority, add the measured net value of that work instead. Do not use $75,000 of payroll as a substitute for its value.
Suppose the next item also takes five weeks with AI. It ships in week ten instead of week twenty. The additional benefit is the net value of receiving that second outcome ten weeks earlier. This is how the advantage accumulates across the portfolio. It only accumulates while the next work is worth doing.
Before funding a roadmap item, put the accepted outcome, baseline delivery cost and time, all-in AI ceiling, expected net value, and measurement date in front of Finance. Use a range when the value is uncertain. Agree on the point where you stop spending.
Some work will justify almost no AI cost. Other work may justify more AI cost than labor. There is no useful universal allowance per engineer because the value and risk belong to the work.
Set a ceiling for the portfolio, then move money toward outcomes that prove their value. Track individual usage for security and misuse, not as a performance score.
The budget question is not, “How many tokens did this engineer use?”
It is, “What did this work cost, what did it return, and what should we fund next?”
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