RICE breaks a candidate feature into four components: Reach (how many users affected per time period), Impact (a magnitude score, typically 0.25–3), Confidence (a percentage reflecting certainty in your estimates), and Effort (person-weeks). Dividing the numerator product by Effort produces a comparable score across items. Because Confidence is explicit, the model penalizes guesswork rather than hiding it.
WSJF, introduced in the Scaled Agile Framework, focuses on economic urgency rather than output size. Cost of Delay is the sum of user-business value, time criticality, and risk reduction or opportunity enablement. Dividing by Job Duration means a small, fast-to-deliver item with high delay cost beats a large, slow item with the same delay cost — a direct counter to the common habit of prioritizing big projects over high-impact quick wins.