Error Proofing An Overhead Projector Case

Error proofing is a concept where systems are designed to help prevent failure.  A common Japanese term is poke-yoke.  There are different levels of error proofing such as prevention, detection, and warning.

Prevention is where the process is designed to work one way and one way only.  An example would be the charger cable for you phone.  The end of the cable is shaped so it will only insert into the phone one way.

Detection is a method that senses something is wrong and lets the process know.  An example would be a piece of assembly equipment that senses all the components are not in the machine and a light turns on, but the equipment can still cycle.

Warning lets someone know how to correctly execute a process.  A colleague of mine showed be a great example of this for our Overhead Projector case.

(Click on image to enlarge)

The group was having a problem with people putting the projector in backwards.  It caused damage one time.  Quick, simple, and easy to understand.  It may not prevent someone from putting the projector in backwards, but it does significantly reduce the chances and makes the right way visual.


Posted on October 3, 2011, in Error Proofing, Tools and tagged , , , , , . Bookmark the permalink. 1 Comment.

  1. The case for my wife’s PPAP machine for her sleep apnea also has poke-yoke in order to prevent damage. The inside compartments are shaped for the machine and there is also a picture depicting the the correct orientation. This was helpful when trying to figure out which way the machine should be placed as well as all its cords and hoses.

    It’s always interesting to see lean principles being used in everyday life situations.

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