Use this monthly. If no one reviews the list, tools accumulate and ROI disappears.
List every AI subscription and its monthly cost. Include per-seat licenses and any API usage billed separately.
For each tool, estimate hours saved per month. Multiply by the hourly cost of the person who does that work without the tool.
Note the error rate: how often does the output require correction, and how long does that correction take? Subtract correction time from your hours-saved figure.
Classify each tool as: paying for itself (keep), breaking even (monitor for one more month), or costing more than it saves (cancel or replace).
Assign one metric per tool — the single number that would make you cancel it if it declined. More than one metric per tool usually means no one is watching any of them.
Review quarterly for tools you marked "keep." A tool that paid for itself in January may be redundant by April if a better option launched or your workflow changed.