The Ninety-Ninety Rule is attributed to Tom Cargill of Bell Labs and states the following: "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."

The quote was made in relation to computer programming but one of the underlying themes of Tools not Rules is that the concepts translate across disciplines. These ideas work for illustrators, designers, bakers, musicians, dancers and more. The Ninety-Nintey rule is no exception.

That first big push, coming up with the ideas and laying the groundwork is the easy part. Wrapping up everything, polishing the idea so it’s ready for world is the hardest part and the push for the final 10% of a project can often take half, or more, of your production time.