Poka-Yoke

 

 

 

 

Poka-Yoke

Poka-yoke can be implemented at any step of a manufacturing process where something can go wrong or an error can be made. For example, a fixture that holds pieces for processing might be modified to only allow pieces to be held in the correct orientation, or a digital counter might track the number of spot welds on each piece to ensure that the worker executes the correct number of welds.

Three types of poka-yoke for detecting and preventing errors in a mass production system

  1. The contact method identifies product defects by testing the product’s shape, size, color, or other physical attributes.
  2. The fixed-value (or constant number) method alerts the operator if a certain number of movements are not made.
  3. The motion-step (or sequence) method determines whether the prescribed steps of the process have been followed.

Three-step analysis of the risks to be managed

  1. Identification of the need
  2. Identification of possible mistakes
  3. Management of mistakes before satisfying the need