u-chart control limits

Calculates basic c-chart limits for an average count of nonconformities.

Calculates the existing sigma-based Xbar limits and Xbar-R chart limits from the grand mean and average range.

Calculates basic np-chart limits from pBar and sample size without automatic process assessment.

Calculates basic p-chart limits from pBar and sample size without creating an SPC chart.

Calculates defects per million opportunities from defects, units, and opportunities per unit.

Calculates defects per million units as an auxiliary quality metric.