airplane rule

( n.)

   "Complexity  increases  the  possibility  of  failure;  a twin-engine
   airplane  has  twice  as  many  engine  problems  as  a single-engine
   airplane."  By  analogy,  in  both software and electronics, the rule
   that  simplicity  increases  robustness. It is correspondingly argued
   that  the right way to build reliable systems is to put all your eggs
   in  one  basket,  after  making  sure that you've built a really good
   basket. See also {KISS Principle}, {elegant}.

[glossary]