Comparing software engineering to classical engineering assumes that software
has the ability to wear out. Software typically behaves, or it does not. It
either works, or it does not. Software generally does not degrade, abrade,
stretch, twist, or ablate. To treat it as a physical entity, therefore, is
misapplication of our engineering skills. Classical engineering deals with
the characteristics of hardware; software engineering should deal with the
characteristics of *software*, and not with hardware or management.
-- Dan Klein