Karakuri – Lean Manufacturing and Six Sigma Definitions

A Japanese word that uses mechanic devices to assist with tasks with limited or no electric, pneumatic, or hydraulic power sources. It is also not controlled by a computer but rather by the design of the mechanics, using gravity, springs, kinematics, counterweights, human muscle, weights, pendulum, seesaws, and gears to manipulate objects.

Within lean, it stands for mechanical gadgets that improve your processes and conveyance systems, also known as karakuri kaizen.

It originated with mechanical dolls in Japan, called karakuri ningyo. These dolls are first mentioned around 1500 years ago, but were most popular around 200 years ago. These dolls can be seen as the precursor to robots.

The principles of Karakuri Kaizen are:

Don’t use the human hand. Move objects automatically.
Don’t spend money.
Use the force of your equipment.
Build it with the wisdom and creativity of the people of the shop floor.
For safety, don’t just rely on paying attention, but build a device that stops automatically.

Benefits of Karakuri devices:

Less expensive – Development time is shorter, materials are less costly (as there are often fewer items involved), and the energy costs are much less (if any).
Easier to maintain – With less costly parts, and more knowledge of how it works, keeping these devices running is simpler.
Easier to improve – Since it is built by hand, it can be changed quickly which promotes continuous improvement
More engagement with team – More people can help build a karakuri device, rather than outsource it to another company. Employee engagement is greater.
Improved safety and ergonomics – Reducing the chance of worker injuries and loss work days
Improved quality – devices reduce human error and mistakes

Examples