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Apps / Sigma Metrics

Sigma Level and DPMO Suite

Translate raw production counts or direct defect-rate values into sigma language. This app returns short-term and long-term sigma level, DPU, DPO, DPMO, DPM, yield, RTY, process Z-score, a six-sigma distance gauge, and a comparison table for multiple processes.

Suite

Choose an input method

Sigma logic: Zlt = NORMSINV(1 - DPMO / 1,000,000), Zst = Zlt + 1.5

Primary input mode

Long-term sigma is based on the observed defect level. Short-term sigma uses the common 1.5 sigma shift convention. RTY is estimated from `exp(-DPU)` when only aggregate defect counts are available.

Gauge

Distance to 6 Sigma

0 sigma Gap to 6 sigma: 1.77 6 sigma

Comparison

Multi-process comparison

Process DPMO Yield Sigma LT Sigma ST
Current run 3,125 97.50% 2.7344 4.2344

Instructions

How to use this app

  1. Choose whether you want to start from unit counts or from a direct DPMO / DPU value.
  2. If using counts, enter units produced, total defects, opportunities per unit, and optionally defective units.
  3. If using direct mode, enter DPMO or DPU and provide opportunities per unit when you want DPO conversion.
  4. Click Calculate to return DPU, DPO, DPMO, DPM, yield, RTY, Z-score, and both long-term and short-term sigma level.
  5. Use Add To Comparison to store the current result in the comparison table for side-by-side review against the next process or time period.

Long-term sigma reflects observed process performance. Short-term sigma adds the conventional 1.5 sigma shift, which is commonly used in Six Sigma reporting.

The sample-size recommendation is a practical guide only. If the process is high risk or the defect level is very low, collect more units before making strong conclusions from ppm-level comparisons.