I was having a window replaced at my house. But it wasn’t a normal window, it was a triple-layer fog-proof 20 ft. x 4 ft. window. Of course, my window space isn’t exactly 20 ft., it’s 19 ft., 53/64 inches. It’s good to have these exact measurements, it’s even better to have them *before* you cut and transport the replacement.
You guessed it—they transported the window, set up scaffolding, raised it up, and it was 11/64 inch too tall. Luckily for me they had to absorb the cost of redoing the whole thing. But the point is, there was a cost, a much higher cost than taking an extra 20 minutes to carefully measure the height precisely before cutting the new piece of glass. Because the replacement would take a week, they had to reinstall the old glass as well. There is a huge headache dimension to factor in. Being inexact in any project’s planning stage can be frustrating, embarrassing, and costly.
The whole experience reminded me of everyday life in software quality assurance. Once you cut a piece of software code and send it to customers, it is very expensive to fix glitches and issue patches. You also look bad in front of customers.
The least expensive time to get precise measurements is during the Requirements stage. Being a good-requirements advocate is also being a friend of the programmer and tester. Get the requirements right, and you’ll make new friends and save money.