Run Chart – A line graph of data plotted over time

• Generally, 25 data points are needed to get meaningful results. However, ” Even as few as seven to 10 observations are sufficient to start” (2).
• Plot the values on the chart and connect the dots.
• Calculate the median and place this on the chart. The median is the value separating the higher half of a data from the lower half.
• In the data set {1, 3, 3, 6, 7, 8, 9}, the median is 6
• In the data set (1,2,3,4,5,6, 8,9) the median is 4+5 / 2 = 4.5

There are many standards for interpreting data from run and control charts.

Among the simplest is the AIAG’s Rule of 7.  This standard was recommended by PQ Systems, now Advantive, and adopted by the American Society for Quality (ASQ) in support of their K-12 Education Initiative.

• 1 point outside of control limits.
• Run of 7 points on one side of the mean.
• Trend up or down of 7 points in a row.
• Recurring cycles.
• Other non-random patterns.

Advantive – Application Rule of 7

(1) Run Chart: Creation, Analysis, & Rules

(2) Right number or Right Action? “Yet another predictable Question” by Davis Balestracci

Additional Standards: QTP Quality Training Portal