SKEDSOFT

Note that chart “designer” or user could use the ARL formula to decide which sample size to use. For example, if it is important to detect 1σ₀ process mean shifts within two periods with high probability such that ARL(Δ = 1σ₀) < 2.0, then sample sizes equal to or greater than 10 should be used. Note also that ARL does not depend on the true mean, μ.