which comes from sci-fi writer Theodore Sturgeon who said,
“Sure, 90 percent of [anything] is crap.
That’s because 90 percent of everything is crap.”
See also 90/90 rule
“The first 90% of the code accounts for the first 90% of the development time. The remaining 10% of the code accounts for the other 90% of the development time.”
attributed to Tom Cargill of Bell Labs, or
“The time from now until the completion of the project tends to become constant.”
attributed to Douglas Hartree.
Hanlon’s Razor – A simple explanation based on cock-up (stupidity) is more usual than a complicated one based on conspiracy (evil). “Razor” after Occam’s Razor.
Finagle’s Law (Sod’s Law) – anything that can go wrong will.