Masaaki Imai in his book, Gemba Kaizen, A Commonsense, Low-Cost Approach to Management, states that any motion of a person’s body not directly related to adding value is unproductive. Some examples of motion waste include:
- Searching for jigs, fixtures, tools, files, etc.
- Bending to lift heavy loads
- Turning to retrieve or dispose of products
- Reaching for components and tools
- Placement of products in the production process
- Walking to printers, fax machines, store rooms, etc.
In addition to causing productivity problems, excess motion can lead to job dissatisfaction, additional strain on employees, absenteeism, and possible injury.
Motion waste can be easily reduced by analyzing the motion an employee makes using a simple tool called a spaghetti diagram. You start by drawing a diagram of the work area. Then using lines document the movement an employee makes in the work area by following them and observing their movement. Figure 1 below is an example of a spaghetti diagram prior to making any changes. It shows an operator making multiple trips back and forth between the machine and their work bench to get tools and needed items to make a changeover.
Figure 1 – Before kaizen event
To improve the situation, the person was given a cart that contains all the tools and items needed for the changeover. Pushing the cart from station to station the number of trips was greatly reduced as shown in figure 2.
Figure 2 – After kaizen event
When analyzing employee motion you quickly realize that very little of their motion is actually productive and most of it can be eliminated by properly laying out the work area. Using 5S, a place can be designated for everything and maintained so the need to search is drastically reduced. Other things you can do include:
- Placing tools at the point of use
- Design fixtures that clamp instead of bolt
- Utilize rolling shadow boards that can be moved to the needed location
- Orient tools for quick use
- Workplace layout
Most important to success is having employees participate in the best way to layout the work area. Solicit their ideas and incorporate as many of them as possible to get the maximum buy-in.