Use a Poisson distribution to represent data where the attribute of interest can appear an infinite number of times. Data include k counts. Listed below are the steps Minitab uses to compute ANOM results for data with a Poisson distribution.

- Computes the overall average of counts:
- c̅ = Σ
^{k}_{i=1}c_{i }/ k

- c̅ = Σ
- Compute an estimate of the standard deviation of the counts:
- s = Sqrt (c̅)

- Determine the decision lines at significance α:
- UDL = c̅ + h
_{α}s * Sqrt((k - 1)/ k) - LDL = c̅ - h
_{α}s * Sqrt((k - 1)/ k)

where h

_{α}= inverse cumulative probability of α2 for the standard normal distribution, where α2 = 1 -α / (2 * k).If the number of rows in your response column (k) equal 2, then α2 = 1 -α / 2

- UDL = c̅ + h
- Plots the counts with the decision lines and the center line.