There's a second 90%

I finished another isolation project yesterday: 68 Bits of Unsolicited Advice, One At a Time. It’s based on Kevin Kelly’s original article by the same name.

It took me a fair bit longer than I estimated: 20 odd hours instead of 12. Towards the end of it, whilst testing stuff, I came across this:

Be prepared: When you are 90% done any large project (a house, a film, an event, an app) the rest of the myriad details will take a second 90% to complete.
The well-timed screenshot from 68 Bits of Unsolicited Advice, One At a Time.

90% of 12 hours is 10.8 hours. Following the there’s another 90% after the first 90% rule: two sets of 10.8 hours equals 21.6 hours.

That’s pretty spot-on.