A major contribution of the Toyota Production System (TPS) is its description of the seven categories of waste (or muda) in the typical production process. Reducing these wastes is the primary goal of a lean production process. (Lean=No Waste.) This is the fifth 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 Overproduction.
Overproduction is simply producing anything that doesn’t need to be produced. There are two basic forms:
- Producing something nobody wants.
- Producing something that people do want, but including something in it that nobody wants.
Going back to the traditional car company, overproduction includes not only making cars for which there is no customer demand; it also includes making car features for which there is no demand, even in otherwise desirable car models.
In a webinar for The Lean Enterprise Institute, John Shook and Jim Womack say that Taiichi Ohno viewed overproduction as the most important kind of waste; indeed, all other forms of waste can be viewed as a kind of subset of overproduction.
It’s not hard to see why overproduction is the worst of the seven muda: There is nothing more wasteful than producing something customers don’t want. No improvement in any of the other wastes (reducing defects, getting rid of excess motion, etc.) will have any effect if the entire process is itself a waste of time because it is trying to meet a demand that doesn’t exist.
There are some historical roots for this concern about overproduction in Japanese car companies. Back when the Japanese auto industry was just getting going, it lacked the money and other resources needed to maintain massive production inventories until demand picked up. Overproduction simply wasn’t an option: If a car was built, it had to be sold, and quickly. This meant that a system had to be developed to accurately sense current customer demand and immediately translate that demand into production as cheaply and effectively as possible. That system was lean production.
To stamp out wasteful overproduction, you need to pay attention to many things:
- Continuously gathering accurate information about customer demand and quickly communicating that back to the production process.
- Building strong long-term relationships with suppliers, workers and customers so that large shifts in customer demand can be met with flexible solutions rather than mindlessly and wastefully churning out surplus inventory or laying off employees.
- Creatively finding ways to level demand while still allowing for wide variety and high responsiveness in production.
- Engaging in strict editing to remove anything from the product or outcome that customers don’t really want, even if their engineers or designers think customers should want them.
The ultimate goal is to create a process where the only thing produced, at any point, is something that creates value for the customer. Everything in a production process that fails to fit this definition is not just pointless, it is a hindrance.
In everyday life, it can be hard to find examples of overproduction without a little soul-searching. Most people feel like they barely have time to take care of the necessities, so the notion that they are generating anything unneeded seems laughable. In the busiest life, however, there are opportunities for editing.
For instance, in our household, it’s ironic that we have a kitchen overflowing with food but never have anything to eat, closets overflowing with clothes but never have anything to wear, and a DVR full of recorded TV shows but never anything to watch. Each of these situations screams of overproduction at some point:
- We are buying and washing and keeping the wrong kinds of clothes, which wastes our time and effectively hides the right clothes from us by pushing them to the back of overfull closets.
- We are buying too much food that we won’t eat and ingredients we will never use.
- We record TV shows based on our aspirations rather than our realities, leading to us filling up our DVR with things we wish we would watch (thoughtful, complex dramas and documentaries) rather than things we will watch at the end of a long day (sitcoms and other junk-tv).
In short, we aren’t overproducing because we are doing too much: We are overproducing because we are doing too much of the wrong things. Our solution isn’t to do less, it’s to become more sensitive to our REAL lifestyle and our REAL demands and try to meet them as effectively as possible.
Even in everyday life, overproduction may be the grandest waste category of them all, so it’s worth thinking about. As Ohno suggested, you will never really reduce waste and get your everyday processes lean if you are making things nobody really wants.