Y2K Remediation as Diagnostic Precedent

The Year 2000 remediation effort, undertaken globally between roughly 1997 and 2000, addressed a problem that was conceptually trivial (two-digit year fields would roll over from 99 to 00, breaking date-sensitive logic) and operationally immense (the code containing the fields had been written decades earlier, by programmers who had since retired, in languages whose expertise had become scarce, embedded in systems whose original documentation was incomplete or missing). The cost — estimated at $300 billion worldwide — was not the cost of the fix, which was in principle trivial. It was the cost of diagnosis: locating every instance of the problem across millions of lines of code in systems whose internal logic had been modified by successive generations of developers, each understanding her modifications but not the original design. Y2K is the canonical precedent for what happens when diagnostic capability is allowed to atrophy and then demanded