So the start of the field of lean construction really goes back to the late 1980's, early 1990's, there was a report that Lauri Koskela wrote on the conceptualization of construction, and project management, and how we were missing out on some fundamental concepts, like, flow and value, that we were too focused on transformation. At around the same time, in the late 80's is a number of people also realized that current project management practices really were not working that we had too many projects that cost too much and too long and I had too much inventory and quality problems and safety problems. And we then realized that some concepts were missing in our world of project management. As far as I'm concerned, the concept that was missing is in we always talk about managing five resources in construction, time and money, materials, manpower and machines, and, we never talk about managing space. And obviously, space is a big, concern in managing any project. And so we need to bring that into the, discussion, on managing projects. And lean of figure us a way to begin to think new ways about how we could manage projects. >> So Lean has been developed in the context of car manufacturing. When applying Lean in construction we have witnessed that many of the principles, methods and tools of Lean are fully applicable in construction. However, the context in construction is different and also new principles and methods are needed the method of Last Planner is the best example of a method developed in the framework of construction. >> I think that it's, you know it's a challenge for us to Apply them from manufacturing to project based production system, especially a different industry with different types of customers where we build mostly custom products, as opposed to mass produced products. And we have a craft tradition, a craft artisan tradition in terms of design and the actual work itself. And we have been through the course of the 25 years of Lean construction. I'm more now. We have been trying to understand how to help people make that change. So I think the principles absolutely apply. My understanding is really that Lean is a way of thinking and instead of practices based on that way of thinking to produce high quality work, quality number one, safely. And then with that focus and, with Lean thinking we figure out the safest best way to produce that type of quality. So, that would be just a short answer in terms of trying to connect. You know, the Lean principles to work. >> [FOREIGN] [FOREIGN] [FOREIGN] >> Well, there have been many different initiatives, and in some places it happens simply by smart people in the industry reading books like the Toyota Way and realizing that they can try some of those tools in construction and perhaps get some benefit from them. But that kind of application is just tools, and it often fails, because the tools are only as good as the people who are running them at one time. And Lean requires, it's an exothermic thing which requires energy to be applied at all times to keep it effective and going. So if you run tools. People running them lose interest, lose their way, lose company and so on. They can disappear. So I think that the real introduction of Lean as an idea and construction as a concept in my mind can be clearly traced to the report from Sci-Fi which proposed the idea that flow and value were equally good ways or special ways of viewing production and construction along with transformation and the power of that idea has been that we can look at flow, value as well, but for my part I find the flow idea a far more powerful one. And so we can then begin to apply that idea of how things flow, and what flows, to all aspects of construction whether it be design, or a procurement, or production on a construction site, or commissioning, or even facility maintenance. And then you begin to have insight into any of those by asking yourself a question. What are the things that flow? How do they flow? And what are the barriers to that flow? What are the [INAUDIBLE]? Now if you look at construction in that way, then you can apply ideas from operations research, from production, from manufacturing, things like little's law, which states that through put is the equal to the amount of work in progress divided by the cycle time for any given unit of production and those are very powerful tools, because they allow us to take our thinking and apply it to other context and invent new tools on new ways of getting results that we want to get.