Attached is MSA example from MSA 4 handbook. I am using the same excel sheet for calculation then how my calculations are wrong?
please help
Your calculations are wrong because people aren't careful. Everyone goes and hacks together an Excel spreadsheet because due to computers today, it's "easy." Then, nobody goes back and TESTS their spreadsheets against known working models. "It's in a computer, therefore it must be correct."
Absolutely false.
You should question ANY spreadsheet you are given, ESPECIALLY if it isn't protected. Copies float around and people trample through them thinking they understand and the click and copy and try to do things quickly - next thing you know, broken formulas start appearing.
There's LOTS of reasons your calculations could be wrong.
That's, in fact, how I learned so much about Gage R&Rs. Suppliers were giving them to me, everyone had their "own" spreadsheet. One day, I had some free time, and started copy pasting the input data between sheets. And found that in MANY cases the spreadsheets did not agree. And I found that not all spreadsheets are created equal. Heck, I found calculation errors in the professional gage management software my own company bought.
So I made a gage R&R spreadsheet and locked it down. That way, I KNEW nobody had accidentally stepped on a formula. And I don't mean to say people were giving me intentional errors to make their gages look better, they were just careless spreadsheet errors, that propagated copy by copy. At that point, we no longer accepted Gage R&Rs other than those done in Minitab or those done on my Excel sheet. We found too many instances where the underlying math was wrong.
Same thing with capability studies.
Now, like I said, *I* may be wrong, but I don't think I am.
PS - It would be nice if the Cove created a library of TESTED sheets. I see a lot of people flinging up sheets. And they are OK (NOT protected). USE WITH CAUTION. So if, say, like this in these comments someone flings up a sheet, great. BUT ... it would be nice if we could submit an "official" sheet to the Cove, have it peer tested and certified, and then have a "Cove approved" tool section. I don't know how that would fit with their mandate or not.