Complexity As Debt

At XpUniverseTwoThousandOne, WardCunningham presented the metaphor of "Complexity as debt" in his closing speech. Here it is:

Skipping design is like borrowing money. (I like "writing code" better than "skipping design" here -- JimLittle)
Refactoring is like repaying principal
Slower development due to complexity is like paying interest
[a later addition] When the whole project caves in under the mess, is that like when the big guys come round and slam your hands in the car door for not paying up?

See also TechnicalDebt, PairingDebt You could refer to this sort of debt as DesignDebt or RefactoringDebt. JohnBrewer suggested on the XpMailingList that it's an effective metaphor to communicate development tradeoffs to people with a business mindset. See http://www.xpsd.com/SoftwareInProcess

Ward explains the debt metaphor in his 1992 OOPSLA experience report and again in a 2009 YouTube video ...