While reading last month’s Contractor, I was intrigued by the article on building information modeling (BIM). Stream of consciousness being what it is, I harkened back some 20-25 years to a time when the ‘hot ticket’ in construction scheduling was a system called CPM, short for Critical Path Method. All of the young graduates from Arizona State University, University of Arizona and Northern Arizona University had been taught to use this method when scheduling and progressing large projects. The general contractors at the time, whether old school or not, embraced this method fiercely.
Meetings on new projects were rife with references to the “critical path” of the project and included “float,” which was a built in fudge factor in case of an unplanned excursion from the critical job path. Float was closely guarded from the prying eyes of the subcontractors, one would assume, in case they were to take advantage of the built-in flex by possibly reallocating manpower to other, just as critical, projects when under pressure to do so. This situation came up more frequently than one might think due to the, as yet unrecognized, manpower shortages that were just over the horizon.
In any case, the planning and execution of projects using CPM began to quell the chaos that was previously the daily bread of large commercial and industrial projects. Project managers were insistent upon subcontractors providing as much detail and time estimates as possible in order to fine tune the critical path. This, in turn, had the effect of making the subcontractors and their sub-subcontractors more aware of their responsibilities toward the success of the project, but also more acutely aware of just exactly how much time and manpower was required to participate in a successful project. That’s where planning came to the fore.
I cannot remember who taught me about the Seven P’s but once learned, if you want to be a success in your field, they cannot be ignored. In case you need a refresher, or maybe have never heard of the Seven P’s before, they are: Proper, Prior, Planning, Prevents, Piss, Poor, Performance. Succinct and to the point, that acronym perfectly frames almost every aspect of the industry. In fact, just about any industry.
Going back to CPM and then looking ahead to BIM, it is obvious that the single most important factor in those programs, and in construction in general, is PROPER PLANNING. Execution would be right on the heel of those plans as well.
Prior to the ubiquitous availability of CAD and today’s computing power, projects were conceptualized by the owners or financiers, designed and drawn by architects—sometimes using templates, but mostly drawing by hand—fleshed out and detailed by engineers and other mechanical specialists. Once plans were completed and a general contractor was selected, the general put out invitations to the various skilled trades to bid from that set of plans. The general, or GC for short, then collated the bids, made sure to have every facet covered, selected his subcontractors and put a budget together. After everyone on the GC side of the project was satisfied, the project would move forward with those subs selected providing time and manpower assessments.
At that point, those who would actually do the work in the field took over. The GC’s project management team called all the subs together by phase and parsed the drawings looking for conflicts and trying to eliminate “oh s%^t” moments before they inevitably appeared. In larger construction projects, this was a daunting task. Trying to envision a three-dimensional space shown on two dimensional drawings is difficult under average circumstances. In, say, a large industrial facility for the likes of Honeywell, or Intel, it was an absolute nightmare.
As an example, how do you accurately plan, layout and install piping and HVAC systems in the ceiling space above a clean room floor without having any conflicts? The short answer is...you don’t. Someone, whether it was an architect, engineer, plumber, HVAC, fire suppression, low voltage cabling, electrician or some other trade, is going to want to run a pipe through a return air duct or a Halon line right where the fire main is going. “Well,” you might say, “they just need to follow the plans!” Not so fast. Humans drew the plans, and humans are fallible. One person sees things going one way (usually an architect or engineer) and the field guys see things a bit differently in 3D. It’s inevitable. At least I’ve never seen it go differently.
Conflict resolution is one of the biggest headaches the field supervision has to deal with, and a good, cohesive team of professionals is a must if the project is to go smoothly. Planning by all trades as regards installation of their piece of the project is critical.
Admittedly, I have not delved into BIM, so I’m inferring from the Contractor article that BIM is accomplished by using detailed CAD drawings for each trade, rendered in three dimensions. The advantage of using computer power with CAD to produce what amounts to an X-Ray plan view of a project is incredible. If you could look at a 3D plan showing exactly where you were to run your piping or duct work, complete with dimensions from building structure, how easy would it be to install your stuff without conflict? The answer is very easy. How easy would it be to make “as-builts” if you followed the CAD drawings precisely? You get my point.
There are a lot of new products, materials and methods emerging in the construction field every day. Some of them are questionable at best and may not be around very long. Others, like BIM, seem to me to be moving the industry in the right direction and are certainly addressing an issue that has needed refining for a long time.
The Brooklyn, N.Y.-born author is a third-generation master plumber. He founded Sunflower Plumbing & Heating in Shirley, N.Y., in 1975 and A Professional Commercial Plumbing Inc. in Phoenix in 1980. He holds residential, commercial, industrial and solar plumbing licenses and is certified in welding, clean rooms, polypropylene gas fusion and medical gas piping. He can be reached at [email protected].