# Description Nominal + Tol − Tol Direction

How it works

Worst-Case (WC): Sums all tolerances assuming every dimension is at its limit simultaneously. Most conservative — guarantees fit but may over-tolerance.

Stack = Σ(nominal × dir), Tol = Σ|tol|

RSS (Root Sum Square): Statistical method assuming dimensions are normally distributed. Smaller stack but accepts low (<0.27%) probability of failure.

Tol = √(Σ tol²)