It would be helpful if @Nics Santos would answer our questions. It seems that they have only limited knowledge of SPC and that they are using a software program that will apply the rules. It also seems that someone is telling them myths about SPC. In my experience it is more likely that they have chosen an incorrect subgrouping scheme or chart type such that the ‘false alarm’ rate is probably the least of their problems.
I think they also want a rote response: to that end in my experience only 1 point out (rule 1) and 2 out of 3 near the same limit (rule 5) are the best and result in very few false alarms, yet will provide enough opportunities to learn about your process and SPC.
I think they also want a rote response: to that end in my experience only 1 point out (rule 1) and 2 out of 3 near the same limit (rule 5) are the best and result in very few false alarms, yet will provide enough opportunities to learn about your process and SPC.
