朝着标准化建筑业信息分类学迈进 - 中国BIM门户 ChinaBIM.com

 
【中国BIM门户黄锰钢注】建筑行业信息的标准化分类问题是让BIM研究者十分头疼的问题。BIM是基于构件的建筑设计，因此对一个建筑物的分解结构（Breakdown Structure）和对建筑全寿命信息的分类结构是一切的基础，也是保证实现各软件协同合作的前提条件。同时，每个构件要细分到什么程度，各个构件属于哪个LOD（Level of Details）也是一个重要的问题。但是，这也是一项十分困难的工作，很难有一个让所有人都认同的建筑业信息分类体系，至少现在还没有出现。美国的CSI（Construction Specification Institute）是这项工作的权威机构。近期，他们推出了OmniClass建筑分类系统，以后我们网站将对其进行详细介绍。

All too common recently is the notion that “system” means computerized or computerization, or relating only to a computer. That is simply not so.

Wikipedia defines a system this way: A System is a set of interacting or interdependent entities forming an integrated whole.

Systems are assemblies (and assemblies of assemblies) that perform a function and systems abound in virtually every living environment or discipline, as well as the constructed world.  So whether it be an anatomical system, a plant life system, an automotive or aeronautical system, or a building system; all those components, materials, tubes, frames, panels, parts, etc., unite to create assemblies to perform a function that handle a specific task and serve the main function or general purpose of that whole system. Generally, each system functions to promote or assist a certain aspect of life.

Taxonomies are systems too. Taxonomy is the practice and science of classification. The word finds its roots in the Greek τ?ξις, taxis (meaning 'order', 'arrangement') and ν?μος, nomos ('law' or 'science'). Taxonomy uses taxonomic units, known as taxa (singular ‘taxon’).

The understanding of evolution is shown in a map displaying the taxonomy of the development of various living creatures, and there is taxonomy of the systems involved in the human body.  There are also taxonomies for numerous domains in the academic world. Taxonomies can be thought of as generalized models as well, and they can be exceedingly helpful in assisting an understanding of complex arrays of elements and in performing complex analyses. There are people who have devoted their lives to this concept and they are called taxonomists.

In one sense, the CSI (Constructions Specifications Institute) is acting as a taxonomist in developing ordered data formats for the building industry.

Taxonomies have their own sets of rules and one of them is that they must be isotropic. Taxa must have a degree of uniformity and similarity.  One might be tempted to call these levels.
 
Systems analysis became a very important new concept in engineering when Admiral Hyman Rickover had overhauled the Navy's way of handling construction projects. He was establishing breakthrough performances because they were developing detailed logic diagrams of the construction and assembly processes that they were involved in.  Critical Path Methods (CPM) and Program Evaluation Review Techniques (PERT) methods allowed models to be built of these complex processes and detailed schedules.

Below is a list of Building Systems that emerged from a systems analysis of the architecture, engineering, and construction processes. It is simply an orderly way of addressing the work at hand from the project management perspective, yet it works to compose and organize all the information in a project in an order similar to the way construction documents are traditionally assembled. It should be self-evident what each of these systems is to the related discipline practitioners.

We are all aware of how a general contractor, or now a construction manager, works. They rip the documents apart and send them along with the specifications to their various sub-contractors.  And in the modern Internet-based project setup, they are simply sent from the design firm. Hence BIM becomes very important for the design firm to affect project control.

The CSI once had a system of some 55 categories and they did not make much sense and were abandoned in the development of the 16 Division CSI format. This afforded a simpler order. But this system was non isotropic, meaning that there were mixtures of materials, disciplines, pre-manufactured assemblies, and engineering systems. There were dissimilarities in the categories.

Developing logic diagrams to define the highly elaborate and very complex AEC processes, or simply doing architecture, as some would have it, led to the creation of a systems based taxonomy of the whole and complete set of architectural, engineering and construction tasks that was shown in Figure 1. In this new world where ISO certification has taken on some importance, such taxonomy becomes of paramount importance because it outlines the general delivery of the work. ISO certification means that a company has carefully defined its work and that it delivers what it has defined. It’s about integrity between the promise and the delivery.

The building systems taxonomy takes on the importance of being the backbone and outline of the work in architecture. The list of building systems shown in Figure 1 are ordered in the way that work is generally installed or “constructed” in a construction project of a building. This order is also defined by the discipline most heavily involved in designing the work in the order of the construction. It should be noted that most sets of architectural construction drawings are ordered in this fashion.

It should also be pointed out that the project specifications can be ordered in exactly the same fashion. By not having a parallel ordering of the specifications, the contractor is placed under the burden of deciphering which specification relates to what on the drawings. The simplicity offered by the parallel use of the same taxonomy in drawings and specifications should be self-evident. This would be also true for estimating, project accounting, and cost-benefit analysis.

By essentially setting up a matrix of the building systems and project time phases, the architectural project manager is able to quickly set up a schedule by backing into it from a breakout of the estimated system construction durations from the projected completion date.

The standard time phases of architecture as defined by the AIA are as follows:

• Program
• Design
• Design Development
• Construction Drawings
• Bid
• Award
• Shop Drawings and Samples
• Construction

Because this list of tasks is more elaborate than necessary on the general level, it constrains and extends the time for a project by inserting too many nodes.  A more coarse grained simplification can be:

• Design & Document
• Bid & Award
• SDS & Fabrication
• Installation

That essentially sets up the whole delivery process.

So the Program, the Design Specifications, the Construction Documents, the Construction Specifications, the Estimating, the Purchasing, and the Fabrication and Installation can all be ordered on a systems basis. In fact, many items already are handled that way.

We live by systems and look forward to the day when the CSI will lead the way in establishing an isotropic systems taxonomy for the work of the AEC world.  And it is my understanding that the CSI has been working upon that for some time now.  Omniclass will soon be implemented and from what has been shown, it appears to be an elaborate assembly of specification data ordered under differing taxonomies. Since we now live in a world which has elaborate databases, adding one more field called Building Systems would make for a powerful way of culling the information as needed in assembling the specifications along with the construction documents. In fact, it could be linked to the CAD process because in CAD, the designers will be defining their systems.

The CSI should take it upon themselves the task of coordinating this taxonomy with the National Accounting Associations, RSMeans Cost Estimating, and McGraw Hill and its Sweets Catalogs. Having a uniform approach is necessary. You design systems, buy systems, install systems, and maintain systems because...

Systems Deliver Function.

About the Author

Lewis M (Bill) Dickens is an architect in Detroit MI. He developed complete logic diagrams of the AEC process as a Systems Analyst at Smith Hinchman and Grylls, where he scheduled the 300,000 sq. ft. SUNY, Stony Brook Medical School which had to be completed in nine months from delivery of the program to the opening of the doors to welcome the newly admitted Med Students. This remains a record project and was written up in the Harvard Business review on coming trends in construction.  Bill’s interest in technology is expansive, including recent designs for the i41CX+ emulator, an advanced programmable and expandable RPN scientific calculator for the iPhone. He recently published an article on wind-powered energy in the AltEnergy eMagazine.

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