R3- BIM

For this week, the assigned reading was chapter 2 of the BIM handbook, where it discussed the history of BIM and the various applications that it has had in the past and how it can be applied today. One of the most interesting points in the article was that BIM was first developed in the 1960s and has been available since the 1980s but only recently has been pursued as a way to design and develop buildings. I suspect that this is mostly because the first BIM programs cost as much as $35,000 and required a lot of memory in order to run efficiently.
The two types of BIM modeling, constructive solid geometry (CSG) and boundary representation (b-rep) are the two main types of BIM modeling B-rep is best described as a wire-frame outline of an object where CSG is an actual filled in object. As Professor Mitchell stated in class, the article goes on to say that BIM modeling was first implemented in the aerospace and manufacturing industries so that they could move their factories towards automation. Boeing and John Deere were the first major corporations to use BIM modeling and Boeing designed their 777 airplanes using BIM and invested over 1 billion dollars in order to reduce the number of design changes by 76,000 and reduce spatial re-work by 90%, saving the company valuable development and construction time.
The article that I read Industry-Wide National BIM Standard: A Progress Report, discussed the building construction's progress towards integrating BIM into the majority of building design. The main problem with using BIM in the construction industry is that there is not a universal file type that can be read by all the different programs that are used in the design and construction of a building so when the architect designs a building and sends it to the structural engineer for analysis, they have to recreate the building in their own program in order to analyze it. The recreation of the building in programs for the architect, structural engineer, precast designer, fabricator, and finally the construction manager takes up a significant amount of time and is one of the main reasons that BIM has not been widely adopted yet. The Precast Concrete National BIM Standard was the first effort to address the industry changes and they demonstrated their first attempt at the PCI convention on October 25, 2011. The article shows how the design goes through the hands of the architect, structural engineer, precast designer, fabricator and CM. They show how an "open BIM" standard can save time and money during the design of a building. "It also showed by example how exchange interfaces can support on-the-fly adjustment of exchanges regarding types of geometry, what level of detail to include, and which properties. An advantage of supporting a set of exchanges is that combinations of exchange components with different functionality are implemented together and can be controlled by the user." As Professor Mitchell also stated in class, the building industry is roughly ten years behind the aerospace industry because every building is unique. While the precast concrete industry is the main focus of the article, they also mention how the American Institute of Steel Construction (AISC) and the American Concrete Institute (ACI) are also working on a "open BIM" system to bring the building construction industry up to speed with the aerospace industry.