Quality Improvement Mistake Proof (Poka-Yoke) Module 38 Mistake Proof Operation Even for processes under control, the possibility of making mistakes exists. The goal is therefore to devise techniques that preclude this possibility Called • poka-yoke (foolproof mechanism) or • buka-yoke (mistake proof mechanism) 1 Foolproofing “The Japanese word for it is “poka-yoke”. It means “foolproof mechanism.” Poka-yoke is used to help the operators work easily by preventing any errors from affecting their output to the next process or function. This prevents defects at the source. Originally applied to machines, poka-yoke can be applied to any process. Only a foolproofed process pletely eliminate operator mistakes that cause defects. Keep foolproofing, or poka- yoke, in mind as you analyze and improve your processes.” Kiyoshi Suzaki Mistake-Proof Operation • Proactive process design for quality Causes of mistakes: üphysical ühuman • omissions • commissions (incorrect action) • extraneous acts (inappropriate action) • sequence errors • timing errors ücombination of physical and human factors 2 System design to minimize human errors • System state feedback clear to operators • Different types of actions have different sequences (command sequence) • Actions are reversible • Consistency in system Strategies Fo
