Jerry Abraham

Thank you Dr. Suresh & Vishwadeep Sir...........this has clarified my doubt. I really appreciate ur time & inputs. Regards, Jerry

thanks kanwal that sounds logical. but it seems there is another school of thought which says that; its is possible for data to be non-normal for a process & the process in reality is perfectly fine. in this case IMR will show process is out of control & the process has to be tweaked - to be in control which in reality might not be required appreciate ur inputs on the above.

I have a basic question - i understand while using I-MR chart the data has to be normal. my question is why must the data be normal.