Re: How we study Gage R&R for automatic machines
It depends on the machine. If it has multiple stations, treat each station as an operator. If it only has one station, you can perform a simple repeatibility study using an Xbar/R chart.
For example, take 10 parts and measure each part 5 times. Plot the average and range for each of the 10 parts on an Xbar/R chart. You can assess the Range chart and the Xbar chart exactly as a standard MSA. You can use the Rbar to estimate the standard deviation for Repeatibility (Rbar/d2), and can use this to calculate the P/T Ratio or %GRR as required. The total GRR will equal the GRR due to repeatibility since there is no reproducibility component.
All normal rules for collecting samples still apply, that is the samples must represent the actual process variation.