Lehman and Belady
Lehman and Belady have studied the history of successive
releases in a large operating system. They find that the
total number of modules increases linearly with release number,
but that the number of modules affected increases exponentially with release number. All repairs tend to destroy the structure
to increase the entropy and disorder of the system.
Less and less effort is spent fixing original design flaws;
more and more is spent on fixing flaws introduced in earlier fixes.
As time passes, the system becomes less and less well ordered...