Q: Which one of the following rules is NOT used for identifying an out-of-control process?
(a)A process is assumed to be out-of-control if a single point plots outside the control limits
(b)A process is assumed to be out-of-control if there is a run of six or more consecutive points steadily increasing or decreasing
(c)A process is assumed to be out-of-control if nine or more consecutive points fall to one side of the centre line
(d)A process is assumed to be out-of-control if two or more consecutive points fall beyond the 1σ limit on the same side of the centre line
Correct Answer: (d)
The correct answer is (b) 'A process is assumed to be out-of-control if there is a run of six or more consecutive points steadily increasing or decreasing'. This question from the General Studies domain tests knowledge of Miscellaneous.