For this test, look for groups of points moving up or down in succession. Count consecutive points, including horizontal runs within the run. This pattern is probably the result of a trend in one of the system resources. The chart below shows a group of seven points moving downward.

Chart made using CHARTrunner.

See also:
>> Analyze for special causes of variation
>> Any point lying outside the control limits
>> 7 or more points in a row above or below the centerline
>> Any nonrandom pattern