"[W]e use the unvalidated decision as our unit of internal inventory, or "work in progress." Each decision that has been made but has not yet been validated by someone (the sponsors, the testers, the marketplace) is still 'pending,' still waiting to show its quality.

"The first lesson that we draw from experiences in manufacturing is to keep work-in-progress down. This is as important in software development as it is in manufacturing, since every decision that is pending costs the organization money.

"The message, in software as much as in manufacturing, is: get the inventory out the door and earning value! Find ways to shorten the pipe."

- Alistar Cockburn