Understanding Karakuri – Automation Is Not Necessarily Complex And Expensive
Automation need not be limited to the complex high-tech robots that many associate with modern manufacturing systems. The principle of Karakuri Kaizen, a central component of the Lean Production System (LPS) philosophy, focuses on simple, easily-implemented automation that rely on natural forces instead of an electrical power supply.
What is Karakuri?
Karakuri originated in 17th century Japan; the most famous example is the Karakuri Ningyo – a mechanical tea serving puppet made out of wood and utilizes a system of cogs, levers and pulleys. The puppet brings a cup of tea to a guest, and once the guest is done, is able to turn around and bring the cup back.
*Video source: https://www.youtube.com/channel/UC3yQ-U_eJjxCNM20mxzgdKQ
In manufacturing, Karakuri is a mechanical system that aims to increase efficiency. The beauty of Karakuri is that it emphasizes on not relying on a power supply, making it very-cost efficient, simpler to install, maintain and easier to improve later on. Karakuri systems depend on natural forces such as gravity, momentum and friction to function.
Karakuri in manufacturing
Karakuri is usually deployed to reduce non value-added work in a process without the need to invest in more expensive systems. Typically, this applies to tasks that have to do with work transfer, loading & unloading as well as assembly.
Take as an example the need to transfer a crate of parts from Station A to Station B, which is a considerable distance away. An option would be installing a conveyor belt, but the design and installation of such system can be costly.
Imagine a pedal-operated seesaw between the stations. When stepped on, the pedal on one side will tilt the seesaw which allows a crate of parts to slide down to the other side. A pedal on the other side of the seesaw will tilt it the opposite way to stop accepting crates of parts or to return empty crates.
Karakuri systems can be as simple as that, or more complex. What is important to understand about karakuri is that it is an ingenious and cost-effective approach to reduce man-hours, parts replenish time and overall product cycle time in the spirit of increasing efficiency and product output.
The concept of Karakuri is not depending in power, allowing the use of materials that are readily available. Not having to depend on electric power means not having to depend on special parts such as electric circuits, which allow the use of simpler materials such as pipes, metal and wooden bars. These materials are inherently more cost-effective to acquire and assemble, sometimes using spare materials from the factory is possible.
Simpler to install and maintain
The basic mechanisms of Karakuri may comprise of a system of pulleys, seesaws, sliders and rotations. These basic systems are easier to design and, because Karakuri systems typically use common materials, it is also easier to install.
Due to the nature of Karakuri systems using simple materials, diagnosing and making repairs to it would not be as complicated as having to repair mechanical systems involving electronic circuitry. Karakuri systems do no necessitate highly-skilled technicians to be available to maintain it, and as such repairs and maintenance to these systems can be done swiftly.
Large room for continuous improvements (or Kaizen)
Karakuri systems are often looked at together with Kaizen – a term to mean continuous improvements. Over time, workers may realise that more improvements can be made to certain production lines, and the Karakuri approach takes that into account.
Using simple materials and simple mechanical systems allow the Karakuri mechanisms to be easily improved in the future. Karakuri mechanism are readily expandable and can be configured to work together with other Karakuri mechanisms.
The benefits of the Karakuri approach
The implementation of Karakuri optimizes energy and working speed, reduces workload, eliminates redundant work processes to increase productivity, all without depending on a power supply.
Designing Karakuri elements into a the manufacturing process ensures that the workers carry-out value-added tasks while eliminating ergonomic issues. An ergonomic work station is one that accommodates the capabilities of worker through a well-designed workstation, work practices and work flow. This avoids excessive efforts during work that is affected by movement and postures of the workers.
Moreover, when a task is taken over by the Karakuri system, the worker can now focus more on value-added work. This will result in higher quality products.
The essence of Karakuri
The underlying principle of Karakuri is the act of continuously improving on tasks using low-cost, but effective, methods not dependant on a power supply.
Developing Karakuri systems ensure that members of a production line always find creative and cost-effective ways to improve the manufacturing process. Being creative and cost-effective has been one of the core philosophies of reducing waste under the Lean Production System.