Y2K: What Went Right?

I've been writing an article about software brittleness and found myself asking a question I can't answer: Why was there so little software chaos in January 2000? There really were hundreds of millions if not billions of lines of COBOL that were at least potentially vulnerable to the rollover bug, those systems really were spread out across a huge variety of industries, including sectors like business and insurance. I've never heard a post-mortem of Y2K that claimed that pre-Y2K remediation efforts were so heroic and wide-spread that the problem was just plain "caught in the nick of time."

In the years prior to 2000, I can at least claim that I cautioned against the most dire warnings. In essays in Software Development and in a letter-to-the-editor in response to a Newsweek editorial, I pointed out that the oft-quoted estimate of \$600M seemed to originate from the worst-case scenario of a single analyst's report, that most PC-based software was written in languages not vulnerable to the problem, and that while errors would certainly crop up (wrong!), many systems would tolerate the computer's belief that the year was 1900. But... I didn't expect the utter lack of effects.

It's a puzzlement.