Cost, Lifecycle Management and "5D"

Okay, it is time for a bit of clarification. In our previous post, 5D was referred to as cost "at least... in my line of work." Einstein's Ghost, we appreciate your comment and we actually happen to agree with you.

The simple fact is that the AEC industry has glommed on to what they think is an easy trend. 3D worked to describe models, 4D worked to describe phasing and timing, so why not apply 5D to cost and lifecycle management? Well, because it is wrong.

When bandying about the "D" (dimensional) terms, we have to keep in mind that these are all based on a particular existing meaning, referring to dimensions, which all have a factual basis in theoretical physics (how is that for an oxymoron - factual basis/theoretical physics - hee hee). But really, the definitions are already set.

Quoting Wikipedia: "There are three conventional spatial dimensions: length (or depth), width, and height, often expressed as 'x', 'y' and 'z'. 'x' and 'y' axes appear on a plane Cartesian graph. In the 3rd dimension, typically a 'z' is used and is found in functions such as a "z-buffer" in computer graphics, for processing "depth" in imagery. The fourth dimension is often identified with time in physics, and as such is used to explain the non-Euclidean space-time used in Einstein's theories of special relativity and general relativity."

3D works for our industry and coincides with the physics definition. We live in a 3D world. Our drawings are 2D, our models are 3D. End of story.

4D works for our industry because it also coincides with the physics definition. When we talk about 4D in BIM, we are discussing the concept of project scheduling and phasing. These are all concepts that work with time, as defined above.

It falls apart at 5D. Again, quoting Wikipedia: "In physics, the Fifth dimension is a hypothetical extra dimension beyond the usual three spatial and one time dimensions. Gerard 't Hooft has speculated that the fifth dimension is really the spacetime fabric.

It has occasionally been stated the Fifth dimension is probability, meaning that the fifth dimension is the full amount of possibilities that could happen or, in other words, alternate realities."

5D simply does not work for industry. It does not coincide with the accepted physics definition. Yes, the AEC industry is using 5D to define cost and lifecycle management. But as an owner, I would not want my costs to be probabilities or alternate realities, I want them to be fact, based on what is happening in OUR reality.

So while we are correct in stating that in our industry, 5D is cost and lifecycle management, that does NOT mean that we agree with what the industry is doing.

Join our movement to ban the term "5D" in the AEC industry. It is, as Einstein's Ghost put it, quite silly and beyond that, totally inappropriate.

Now, what should we call it...?