This is just another scam sold by Dogbert to the Pointy-Haired Boss.
Time spent in chair doesn't equal productivity. I could put an inflatable Bozo doll in my chair and be just as productive.
Time spent typing doesn't equal productivity. I'm not a typist, my product is software, not letters in a document.
Lines of code certainly don't equal productivity, since I consider many of my most productive days to be those when I end up with fewer lines of code than I started with.
You cannot measure people with Procrustean standards and fixed metrics. All those are is a lazy managerial excuse. You can use them as a club to threaten to fire people. You can make an idol of them and worship it instead of actually spending time walking the trenches to see what's really going on.
If you reward people for digging up red jelly beans and punish them for digging up blue ones, you can rest assured that there will be cans of red paint everywhere and people will spend a lot of time that could have been employed digging up jelly beans painting them instead.