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Categories of Waste: Why They Don’t Really Matter
Taiichi Ohno divided waste up into seven forms. Since then, there have been several other versions of the categories of waste (CLOSED MITT, for example).
As a refresher….
The Categories of Waste
- Defects
- Overprocessing
- Transportation
- Motion
- Waiting
- Inventory
- Overproduction
Why the Categories of Waste Don’t Matter
Breaking waste into categories does have many benefits. First of all, they provide a way of organizing your mind when you evaluate a process to identify its wasteful activities. Before I review an operation, I always look at a list of the categories of waste. It keeps my mind sharp and open to the different ways waste creeps into a process.
Categories of waste are also useful when it comes time to make improvements. For example, all of the transportation waste you identified may be fixed with a redesign of a work cell’s layout. All the inventory waste may be eliminated by putting kanban in place.
The reason I say that the categories of waste don’t matter, though, is that people get wrapped up on trying to identify precisely which category of waste something falls into. A pallet of parts on the ground is a waste of inventory. But it also adds the waste of transportation to get to the far side, and possibly a waste of waiting when a forklift comes in to move around the pallets.
In some cases, I’ve seen people get into heated debates over which category of waste a particular activity should fall into. The ironic part…it is a very wasteful way to approach waste reduction.
The key is just to identify that something is waste. Don’t worry about getting the category of waste absolutely right, because eventually, all of the wastes you identify should end up in the same category…‘eliminated’.
Click here to download a waste recording form to help you identify and eliminate waste in your area.
2 Comments
Tim McMahon · October 20, 2009 at 4:17 pm
I agree that waste is waste and it should be eliminated or reduced but I think the categories do matter. It is especially important when learning about waste and non-value added tasks. People can’t see these wastes well in the beginning. To a trained well experienced observer you are right, they recognize the waste for just that non-value added activity.
Jeff Hajek · October 20, 2009 at 4:54 pm
Tim,
Yes, the categories are helpful for recognizing waste. What I’ve found, though, is that some people get worried about mis-categorizing the waste that they identify, and spend too much time debating what bucket is the correct one to drop it in. Once they’ve identified that something is waste, there’s not much incremental value in distinguishing between types.
By the way-nice article on the DOWNTIME waste acronym. I’m adding that into the post.
Jeff