The Toyota Production System (TPS) lays out seven categories of waste (or muda) in the production process. The reduction of these wastes is the most important step in developing a lean production process. (Lean=No Waste.) This is the fourth in a series of posts describing each form of waste and where it can be found in everyday life.
The seven muda are Defects, Inventory, Motion, Overprocessing, Overproduction, Transportation and Waiting. This time we’ll talk about Overprocessing.
Overprocessing is simply the act of handling, working on, or otherwise dealing with something more than is necessary. Since processing anything, in any way, consumes resources like time, labor, and space, doing it any more processing than you absolutely have to is a waste.
Overprocessing can occur for many reasons:
- Lack of obvious completion cues – If you’ve ever run a dishwasher full of clean dishes again because nobody told you it was “done,” you’ve experienced this kind of overprocessing.
- Lack of organization – When items are hard to locate, you are forced to sort through many items over and over again as you try to track down what you are looking for. You are overprocessing your stuff because it isn’t organized well.
- Lack of clear direction – Sometimes we handle things just to feel like we are doing something useful with them. Then we put them down with nothing having been accomplished, and come back to them later to putter around aimlessly with them again. This is one method of maintaining a “procrastination field” that seems like work, but is not.
- Improper completion of tasks – When you do something wrong, you often have to do it all over again just to set things right. For instance, accidentally I often used to use adult laundry detergent to wash our baby clothes, which meant I had to wash them again to avoid irritating our newborns’ sensitive skin. (I’ve since solved this problem with the simple habit of storing the baby detergent next to the baby clothes basket, so I never see one without seeing the other.)
In the traditional automobile industry, this need to rectify defects was the most common source of overprocessing-related waste. Fast-moving assembly lines and quota-focused supervisors didn’t leave time for dealing with mistakes, so they were passed down the line until the end where a team of skilled rework technicians would spend time fixing all of the accumulated mistakes. All of that rework was overprocessing, work that could have been avoided had it been done right the first time.
(An aside: As we go through these forms of waste, it is obvious that they tend to be related to each other. For instance, the more inventory you have to deal with, the more wasted motion you will experience as workers move around to deal with all the extra stuff. By the same token, the more defects you generate during production, the more overprocessing you will do as you waste time fixing things that never should have been broken to begin with. This interdependence can make solving problems rather knotty at times, but it also means that sometimes solving one issue will solve several other related issues at the same time, a nice bonus.)
There are many opportunities for overprocessing in everyday life. Handling the same piece of mail over and over again because you haven’t responded to it or filed it away, washing the same dishes or clothes multiple times because they are never done properly, having the same conversation over and over again because you never get to the underlying issue… Overprocessing is insidious because it often seems cheap and often seems unavoidable.
However, there are many ways to handle overprocessing in everyday processes.
- Instituting a “handle each piece of mail just once” policy for postal mail (or an “Inbox Zero” policy for email).
- Going through a Five-Whys procedure to figure out why clothes or dishes aren’t getting done without defects.
- Doing some self-examination to uncover why you can’t speak your mind instead of having the same conversation loop popping up repeatedly.
And so on. There are as many possible solutions are there are possible problems. The important thing to remember is that overprocessing IS a problem. You can’t avoid processing things in a production process: That’s what a production process is. But processing things that do not need to be processed (or processing them more times than they need to be) doesn’t help you create what you are trying to create, which means that it’s an obstacle rather than an accomplishment.