Identify Waste text
I've talked about eliminating waste throughout this course, and I can't do a course in Lean without spending a little more time talking about the elimination of waste and the different kinds of waste that we need to seek out and do away with. This is a core tenant of Lean, and it was one of the keys to the success of the Toyota way. One of the architects of this theory at Toyota was Taiichi Ohno who identified seven types of waste: Overproduction of goods not needed, Inventories of goods awaiting processing or consumption, Defects in products, Unnecessary processing, Unnecessary movement of people, Unnecessary transport of goods, and Workers waiting on work. I'd like to take a brief look at each one of these just to see if we can identify how they may or may not fit into construction. The first was overproduction of goods not needed. And in construction, I think this is represented by all the excess scrap that we produce, and we produce a lot. It's interesting that we also have this movement towards green building that emphasizes recycling that scrap as contributing to making construction more green when in reality it's much greener to work on producing less scrap in the first place. Number two was identified as inventories of goods awaiting processing. Another way to state this is work waiting on workers. In my opinion, this is a huge one in construction. This is work that's ready, but we're waiting for the trade to show up. Whether they're late or the last trade has just finished early, it doesn't matter. It's all the same. It's all work not getting done because we're waiting on workers. I think this idle time is a huge source of waste in our industry. Defects in products is next, and I have just two words there: punch list, or maybe even one word, rework. There are a lot of things that we have to fix or redo at the end of a construction project and a lot of reasons that this occurs, but it all represents waste that we need to eliminate. The next three, unnecessary processing, unnecessary movement of people, and unnecessary transport of goods are all sort of related on a construction project. How many times do we end up working in a less-than-optimal manner because another trade is in the way? We're waiting on more information from the designers, or we just can't locate our material on a job site. And some of that probably contributes to waste number seven, which is workers waiting on work. Whether it's one trade waiting on the crane or another trade that can't work because someone is in the way or the previous process isn't quite finished, this is another big area of waste in construction. These seven types of waste identified by Ohno as he developed the Toyota production system between the 1940s and the 1970s were the types of waste that he saw occurring everyday in their plant. The relentless pursuit of the elimination of all of these types of waste brought tremendous overall improvement to Toyota's manufacturing process. Now, I just went through and discussed very common examples of each one of these types of waste that we can most likely find on any construction project. That means that seeking out this waste that we know exists might also result in dramatic gains in productivity on our projects and within the industry as a whole if we begin to focus our attention on them.
