Thus, you should expect more variation between part averages, and the graph should show that most points fall beyond the control limits. The parts that you choose for a gage R&R study should represent the typical part-to-part variability. Xbar chart by operator Shows whether most points fall beyond the control limits. If the operators measure consistently, the points will fall within the control limits. R chart by operator Shows whether any points fall above the upper control limit. In an acceptable measurement system, the largest component of variation is part-to-part variation. The gage R&R graphs provide information about the measurement system.Ĭomponents of variation graph Shows whether the largest of component of variation is part-to-part variation. For more information, go to Is my measurement system acceptable?.
Because the %Study Var, the %Tolerance, and the %Process are all greater than 10%, the measurement system might need improvement. Minitab displays the %Tolerance column when you enter a tolerance value, and Minitab displays the %Process column when you enter a historical standard deviation.Īccording to AIAG guidelines, if the measurement system variation is less than 10% of the process variation, then the measurement system is acceptable. The %Study Var uses the process variation, as defined by 6 times the process standard deviation. Use the percent study variation (%Study Var) to compare the measurement system variation to the total variation. Values for %Process are not displayed because they are identical to values for Historical standard deviation is used to calculate some values for StdDev, Source StdDev (SD) (6 × SD) (%SV) (SV/Toler)