In a variables control chart, which of the following is likely to occur if seven points, either increasing or decreasing, are in succession?
A) erratic behavior
B) nonrandom event
C) process drift
D) natural variation
E) process run

Question

Quizplus · Accepted Answer

Seven consecutive points in the same direction (either increasing or decreasing) indicate process drift, which is a shift in the average level of the process. This is different from natural variation, which is the normal fluctuation of a process within its control limits. Nonrandom events and erratic behavior refer to patterns that are not expected in a control chart, while a process run is a pattern where all points fall on one side of the average.

In a Variables Control Chart, Which of the Following Is