Prior to this, Hamming states that field maintenance tends to dominate all expenses in the long run, which brings to mind technical debt. Perhaps all technical debt is a result of not making field maintenance central to the design of the software- it certainly seems like things that occur in the field (in the wild, we call it, or production), that can't be readily remediated, tend to be one of the most common sources of technical debt, though this draws from my somewhat limited personal experience.