The actual return rate your business generates. If it exceeds your MARR (minimum required rate), the project is viable.
↳ Analogía
It's the interest rate your investment is paying you. If your bank gives 10% and your business gives 35%, the decision is clear.
Ejemplo numérico
IRR > MARR: the project earns more than your minimum threshold — accept. IRR < MARR: it earns less than the safe alternative — reject.
With the same flows from the NPV example, IRR ≈ 15.2%. If your MARR was 15%, the project barely passes — sensitive to any forecast error.