This report was issued by the Social Security Administration in 1995. The SSA had been working on its repair for four years by then. Notice its description of the problem: ". . . looking for a needle in a haystack" (p. 1). Worse: ". . . the painstaking execution of the solution is awesome. The sheer size of the problem is the first of these. Dates are everywhere. . . . Most large corporations and government agencies have thousands of programs containing millions of lines of code" (p. 1). Programmers who wrote the original code did not always use dates to identify dates. "A date field can be called date, or it can be called ballgame" (p. 1).
What is true for Social Security is true for every large-scale revision. This is why this document is so important.
There is a huge problem that no one likes to talk about: MISSING SOURCE CODE. "No data processing installation wants to admit it but it is almost a certainty that no installation is free of it unless they have already made their Year 2000 changes. The problem is that modules continue to run in production, but cannot be modified because the source code used to create them has been lost. In a normal environment these modules can run for years if they don't need changing and don't stop working. But because of the Year 2000 issue they must be 'disassembled' and examined to see if they contain code which operates on dates. There is no easy way to do this" (p. 2).