Poka Yoke

Poka Yoke: 

 A design approach to quality that places the responsibility for preventing defects within the design of the product and/or production process.

Approaches: 

Design- Within the product design specifications replace those specs which require defect prone Processes/components with those that require non-defect prone Processes/ components.

Processes/fixture- Within manufacturing replace those Processes/fixtures which are defect prone with those that are not.

Example:

 

Design: "We have been disconnected"

        An electronics manufacturer had three circuit cards connected by flex cables which were hand soldered into the boards. A high scrap rate was noticed with the boards. Occasionally operators would burn the boards while soldering. Some cables were snapped off during integration. Often test failures required the cables be removed for diagnosis and boards would be damaged during rework. The boards were redesigned with telephone jacks which would be soldered on using the normal solder wave equipment. The flex cables were replaced with phone cables which were installed during the integration process.

Example

Process/ fixture: " Our rivets rattle"

       Stainless steel rivet are notorious for their sensitive to proper installation. The rivets head must be flush and at a 90degree. Angle to the installation surface for proper installation. One manufacturer placed a collar with an on/off switch on the ends of it's rivet guns. The collar prevented improper alignment and the switch Forced the rivet to be flush before the gun would fire.