revised :
While I agree 100% that a mechanical counter would be the most straightforward and easiest to implement, and the last thing to fail....
If you used a power failure circuit like Mr. 'Chopped-Liver' offered using a Super capacitor and it just went on to power the micro, and the power fail part of the sketch wrote to the eeprom for that day, you would have a record of the last count when power was lost.
if you data-log, you will be able to know how many parts you made per day.
with an electronic counter you can see trending of how fast parts are being made and what happens at certain times a day.
it would show when you are more efficient and when your machines are breaking down
and how many hours (parts) you lost due to a failure, things like that.
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unintelegable speech to text below
I agree I'm a cannibal counter[ mechanical counter ] would be the most straightforward easiest in flovent [ implement ] and Lasting [ last thing ]to fail however if you day the log [ datalog] you'll be able to know how many parts you need per day with electronic counter you can see trending of how fast part 2 being made what happens certain times a day when you're more efficient when your machines breaking down how many hours you lost things like that
Text from speech on my cell phone on my ride home sorry for any spelling mistakes
I made fewer mistakes the other 79000 hours today