reinvent the wheel

reinvent the wheel
 v.

   To design or implement a tool equivalent to an existing one or part of
   one, with the implication that doing so is silly or a waste of time.
   This is often a valid criticism. On the other hand, automobiles don't
   use wooden rollers, and some kinds of wheel have to be reinvented many
   times before you get them right. On the third hand, people reinventing
   the wheel do tend to come up with the moral equivalent of a trapezoid
   with an offset axle.
    

reinvent the wheel

   <jargon> To design or implement a tool equivalent to an
   existing one or part of one, with the implication that doing
   so is silly or a waste of time.  This is often a valid
   criticism.  On the other hand, automobiles don't use wooden
   rollers, and some kinds of wheel have to be reinvented many
   times before you get them right.  On the third hand, people
   reinventing the wheel do tend to come up with the moral
   equivalent of a trapezoid with an offset axle.

   [{Jargon File}]

   (1997-04-12)