The Toyota Production System (TPS) describes seven different categories of waste (or muda) in the production process. The elimination of these wastes is the most important step in creating a lean production process. (Lean=No Waste.) This is the third in a series of posts describing each form of waste and where it can be found in everyday life processes.
The seven muda are Defects, Inventory, Motion, Overprocessing, Overproduction, Transportation and Waiting. This time we’ll talk about Motion.
In the lean perspective, the muda of motion or movement refers to unnecessary movement of people as they perform tasks that are necessary to complete the product or process. Motion is deemed unnecessary when it adds no value to the product being produced or process being completed.
Traditional auto assembly plants tended to have a great deal of wasted movement as specific personnel assigned to various tasks (housekeeping, tool repair, parts supply, quality inspection, and sick-day filling-in) bustled around the plant trying to keep things running smoothly. The classic book on lean automobile production, The Machine That Changed The World, described the aisles at traditional car factories as being full of personnel running from place to place, none of them directly contributing anything of value to the cars being made.
Lean automobile factories, on the other hand, are noticeable for the lack of personnel found in the narrow aisles. The tasks of housekeeping, tool repair, parts inspection, quality inspection and filling in for sick workers are all performed by the assembly teams themselves without leaving their own work area. This is possible because the assembly teams, being the ones actually assembling the cars, are the best authorities on what is necessary to keep their work proceeding smoothly.
There are many ways to find examples of unnecessary motion in everyday life. These wastes fall into two main types:
- Unnecessary movement of the person through space, i.e., pointless walking around. A good example of this is making unneeded trips back and forth to the garbage can next to the garage because trash day keeps catching you off-guard and wastebaskets fill up at erratically different rates.
- Unnecessary movement of the person’s limbs and other body parts, i.e., waving your hands around more than necessary. A good everyday example of this is stopping every few seconds to open a trash pail to toss out trimmings while you cook a meal.
There are a number of ways to handle each of these issues. For instance, establishing a set trash routine and correctly calibrating the size of wastebaskets to match the demand for them can help reduce all those trips to the dumpster. And keeping a “junk bowl” on the counter to fill with various trimmings as you cook, to be dumped in the trash all at once when you are done, can cut down (pun unintended but inevitable) on those repeated trashcan openings.
There’s a big counterargument to be made when the Motion issue is brought up in everyday life rather than in a factory: Human bodies require plenty of motion, and modern lifestyles really could often use a little more of it for health reasons rather than a little less.
This is true as far as it goes, with some caveats. First, not all motion is good for you: Repetitive strain injuries, most common with the second type of motion listed above, can cause horrible discomfort and any wasted movements causing are well worth eliminating for health reasons.
Second, it really all comes down to the value question: If the motion you are achieving (e.g., trips to the garbage can next to the garage) gives little of value to you or the people you care about, what’s the point of continuing this wasteful practice just to get a little movement into your life? Better to spend some of your time doing a movement you enjoy (swimming, walking, cycling, etc.) to burn those calories and build your cardiovascular system, where the movement gives both health benefits and something of value to your day.
Motion may not be the biggest form of waste in a process, but it can be the most aggravating, as anyone who has had to make one too many trips to the grocery store because she forgot one item can tell you. It’s well worth pondering when you are trying to make your everyday life leaner.