Information Technology Reference
In-Depth Information
Problem avoidance: The problems with the passport system appear to be a com-
bination of performance issues with the software and logistical problems with the
passport agency itself. Putting in a new system without training the personnel in
how to use it is a major management error, not a technical problem.
Neither inspections nor static analysis nor requirements modeling would have
found the logistical and staffing problems, although no doubt participants in the
inspections would have warned management to be careful.
Performance and load testing should have found the performance problems
with the new system, but apparently they were either not performed or not per-
formed with realistic workloads.
2000: The Y2K Problem
The famous Y2K problem is a classic example of shortsightedness. When com-
puter hardware was expensive and memory space limited, it seemed like a good
idea to store dates in a two-digit format rather than a four-digit format. Thus, the
year “1999” would be stored as “99.” This compression of dates started in the
1950s and caused no problems for many years.
However, because dates are often sorted in ascending or descending order, a
serious problem would occur at the turn of the century. Obviously, the year “2000”
in a two-digit form of “00” is a lower mathematical value than “99.”
Millions of software applications in every country used the two-digit date
format and sometimes used it in new applications as late as 1995 when it was
clearly obvious that time was running out.
Starting in about 1995, thousands of programmers began the labor-intensive
work of converting two-digit dates into four-digit dates. Fortunately, the web and
the internet were in full swing, because they allowed easy communication among
Y2K personnel in sharing information and even sharing reusable code for affected
applications. The fact that Y2K problems were not as severe as anticipated is due
to the communications power of the web.
Y2K was not a pure programming problem. The two-digit date fields started
as an explicit customer requirement, often in the face of warnings from software
engineers that the dates would cause trouble.
Lessons learned: The lessons from this problem are not yet fully understood, even
in 2013. For example in the year 2038, the Unix internal clock will expire, and
this will trigger another set of mass updates. Fairly soon, digits will be added to
telephone numbers. At some point, digits will be added to social security numbers.
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