Refer to: http://elsmar.com/Error_Proofing/sld004.htm Poka-yoke: From Wikipedia, the free encyclopedia Examples include: automatic transmissions: the inability to remove a car key from the ignition switch of an automobile if the automatic transmission is not first put in the "Park" position, so that the driver cannot leave the car in an unsafe parking condition where the wheels are not locked against movement. (An example of a Trapped key interlock). 3.5" floppy disk: the top-right corner is shaped in a certain way so that the disk cannot be inserted upside-down. In the manufacturing world an example might be that the jig for holding pieces for processing only allows pieces to be held in one orientation, or has switches on the jig to detect whether a hole has been previously cut or not, or it might count the number of spot welds created to ensure that, say, four have been executed by the operator. high-security padlocks: it is impossible to remove the key from some high-security padlocks unless the shackle on the padlock is closed. Only by locking the padlock can the key be removed. Security mistakes/accidents are therefore much less likely to occur, particularly where the padlock key is kept on a chain attached to someone's belt. This is because the design ensures that a key cannot easily be left in an unlocked padlock, or a padlock left unlocked after opening it, or not fully closing the shackle of a padlock. Each of the ...