Detects process shift using tests on the input points array. Tests applied to detect process shift: Pattern 1 - Ten out of eleven consecutive points on same side of the center line. Pattern 2 - Twelve out of fourteen consecutive points on same side of the center line. Pattern 3 - Fourteen out of seventeen consecutive points on same side of the center line. Pattern 4 - Sixteen out of twenty consecutive points on same side of the center line.


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Inputs/Outputs

  • c1ddbl.png points —

    points contains the points plotted on the control chart, which normally is the output of one of the control chart VIs, such as an x-bar array.

  • cdbl.png center line —

    (DBL) - the center line from the control chart.

  • ibool.png process shift detected —

    (Boolean) - If true, the VI detected one or more of the four patterns.

  • ii32.png first point of shift —

    (I32) - If process shift detected is true, this outputs the index of the first point in the detected process shift.

  • iu16.png pattern # —

    (U16) - If process shift detected is true, this outputs the number of the first pattern [1 to 4] the VI found.

    • Process Shift Detector Details

    This VI searches for the following patterns that signal a process shift:

    • Pattern 1: At least 10 out of 11 consecutive data points are on the same side of the center line.
    • Pattern 2: At least 12 out of 14 consecutive data points are on the same side of the center line.
    • Pattern 3: At least 14 out of 17 consecutive data points are on the same side of the center line.
    • Pattern 4: At least 16 out of 20 consecutive data points are on the same side of the center line.