CAD-Layered Record Drawings for Facility Management
It is time to "raise the bar" for CAD documentation by reflecting on how we got here and where we go from here. To do this, we will address the issues associated with CAD layering in a two-part commentary beginning with the current process of building the computerized design drawing.
So what are the issues? First, the CAD documents that we to turn over to a facility manager have been layered by the design team for the design team's needs. These documents don't exactly reflect what the facility manager requires since building operation and maintenance is not part of the design business.
What is needed is a culture change in how the design community and construction industry compile contract documents and then turn these drawings over to the enduser and what these documents should include at the point of transition to the owner.
Secondly, and to reinforce the need for enhancement in CAD production, we need to recognize that our documents are intended to meet our design needs, as well as the construction team's building requirements. This documentation effort probably spans a building program phase of two to three years. A culture change is also needed to keep in the forefront of CAD application the knowledge that a building will have a useful service life of 40 years or more.
How valuable are CAD record drawings, developed for a two- or three-year need when the building owner has a need for CAD documents that will span 10 to 15 times that period? Can't we see the forest for the trees?
Today we have the opportunity to rethink how computer-generated drawings can be used. It is this thought process that will take us beyond the immediate criteria for CAD contract documents and will meet the need to make CAD facility management documents possible.
Through vision and time management skills, CAD record drawings can be layered to meet the needs of facility management over the life of a building and to do so on day one of building occupancy. Additionally, CAD facility management drawings can be developed as an additional service under the new AIA B281 document for facility support services.
For those who were in the building design business back in the late 1970s and early 1980s, you will recall how we "cut our teeth" on computer-generated drawings. It was a frustrating and costly period for us Neanderthals, who grew up using a drawing board with a straight edge and mechanical pencils. How was this computer-generated process ever going to be cost effective? We even requested an additional fee to use CAD on our design projects.
For the construction industry, CAD mechanical-electrical coordination (MEC) documents would take another 5 to 10 years before the trades would painfully learn how to use this high-tech design tool.
Today, CAD documents and CAD MEC field coordination is now an industry standard. Along the way, there have been several professional organizations and government agencies that have established standards for layering drawing data on a computer-generated document.
Following suit, building owners have embraced and/or adjusted industry CAD guidelines to establish their own layering requirements. Many large institutions and businesses, with multiple buildings, now have their own CAD layering standards. Unfortunately for building owners, most institutions have followed the design community's layering guidelines rather than establish and utilize a layering process based on operation, maintenance, and management of buildings.
Another shortcoming of the design and construction community-provided CAD record drawings becomes apparent when the enduser is not computer literate, doesn't have the computer hardware capacity or software license to use CAD files, and/or doesn't have the budget to effectively use these files.
This can be further complicated by the need to educate the facility staff to embrace the potential application of record drawings as a means to operate and maintain the building infrastructure. Analogous to building a Model A Ford in 2002, providing CAD drawings was an innovative idea years ago. Now we need to produce a vehicle for today and tomorrow.
The Process (or CAD 101)All CAD systems use layers, also known as levels (Figure 1). For this discussion, we are going to use AutoCAD(tm) terminology, as it is widely used throughout the industry. Each layer can be controlled as to its line type, color, and display. Layers could be as few as one, or as many as 100.
The purpose of a layer is to organize each type of element such as walls, windows, and piping with each residing on its own specific layer. A layer system or standard denotes where drawing elements should be located on a regular basis. The color display, line types, and plotting/printing characteristics are also defined in the CAD drawings.
One example is the U.S. Coast Guard standard that complies with the Construction Specifications Institute (CSI). With a set of standards, the layering system uses a general category for each division. For instance, the layer series 16000 is used for electrical. More specifically, you would find electrical panel boards on layer 16400. You can also designate a status of the residing entities, in this example, 01 would indicate an existing design. Thus the name would appear as 1640001 and indicate it is for existing panel boards.
Similarly, the American Institute of Architects (AIA) has an alpha-based system to indicate the type and status. A letter of the discipline, followed by a dash, and then a four character major descriptor dictates this. An additional minor descriptor and a status may follow to further note the state of a layer. These are also separated by a dash. Continuing with the electrical panel board example, an AIA layer would be labeled as E-POWR-PANL-EX.
From a consulting engineer point-of-view, the Richard D. Kimball Company (RDK), a Massachusetts-based consulting engineering firm, uses a layer standard that is based primarily on the AIA principles. RDK has modified the standard to suit its building design needs (Figure 2). Using the panel board example once again, it would be labeled as E-POWR-EXST. Other consulting engineers have their own modifications to the template.
There are other types of layer standards based on other computer-generated software and/or organizations that use CAD software. The importance is not what layer standard a firm incorporates, just that they do establish a system that everyone associated with the project can use as a logical, orderly system to organize the drawing information. This process is specifically intended to greatly improve the communication between the design architect, consulting engineers, and/or D-B firm as well as to "keep the aspirin in the medicine cabinet."
How Facility Management Can ContributeThe enduser, either the property manager, owner, or maintenance technician, can choose different schemes to maximize the application of computer-generated drawings. Currently, a facility manager may see building systems through what we would categorize "today's traditional CAD record drawings," such as the sanitary piping layout to quickly check where all the pipe cleanouts are in case of a blockage in a pipeline. On another occasion, this person can quickly call up an electrical power scheme to see where all the fuse panel boards are located.
Architect and design engineers tailor their standards to assist themselves with their specific criteria to perform work. The enduser can have the same option with a change in the mindset of the design and construction industry. To do so, building owners will need to have their own standards and schemes, as the function of the CAD drawing changes to a different CAD purpose. With the foresight to establish layer standards and schemes that will allow a relatively easy translation from design to enduser, commissioning of facility management of record drawings can be achieved.
Next, You SchemeA scheme is a group management setting for all the layers (Figure 3), and it specifies particular properties of the layer. For instance, it controls the line type, color, display on or off, and plotting information. Multiple layer schemes within a layer standard could be used in the design process to view another trade's work, to coordinate between the disciplines, or to show a different discipline's work out of function. Different phases of construction are another example where a scheme can package various layers together such as showing installation in sequence based on the contract schedule (e.g., base job and tenant fit-out).
There are several ways in which to translate between layer schemes. Script files, Auto LISP, and AutoCAD's "Layer Translate" are ways in which to automate the process. After determining the schemes to be used, the CAD document coordinator can set up a migration tool to change easily from one layer standard to another.
For example, a script file approach is nothing more than text file that AutoCAD uses to run a list of commands. In this case, it could be used to change the layer name, color, line type, etc.
The drawback to this method is possible layer name errors, maintenance, and a need for a good working knowledge with AutoCAD commands and scripts, especially the "layer" command. Also all layers in the migration from one scheme to another need to be predefined, otherwise the function will not execute properly.
The benefit of this CAD management approach is that multiple drawings can be processed at one time. This type of scheme translation, or script file, may require maintenance if new or revised layers and or settings needed to be applied as needed.
The AutoLISP method is a programming language that AutoCAD can interpret into a routine or actual command that can be called on when needed. This process works similarly to the script.
The disadvantages to this method are that only one drawing can be migrated at a time and a good knowledge of AutoLISP programming and program maintenance is required as the user or someone else would need to program the translation. In this situation CAD management will be a factor to contend with, and it is not necessarily a task that can be easily resolved by facility management, unlike the design firm that has CAD expertise in-house.
The final "scheme" that we are going to describe here is using AutoCAD's 'Layer Translator' feature (Figure 4). This method takes a template drawing that has been set up with the layers to a new layer scheme condition and compares it to the incoming drawing. The translator is a powerful tool with which you can easily control the layer properties, and unlike the script and AutoLISP processes, you can maintain easily the template drawing to modify the current layer scheme.
Another feature of the layer translator is that you can apply this to a series (batch) of drawings. In addition, the 'Batch Layer Translator" has the ability to migrate a series of drawings from one scheme to another. Reconfiguring the layers of the design documents to match an O&M scheme is easily achievable. Once either the design firm or the O&M makes a translation, you can show only the relevant information (e.g., show all emergency shutoff valves). The O&M could also adapt drawings from other sources to comply with their scheme.
The Next Generation of CAD DocumentsReferring back to that two- to-three-year building program period where CAD documents evolve but then become the mainstay of record drawings conditions for the next 40 years, the building industry needs to rethink what the facility manager ends up with on day one of building occupancy.
The optimum time to apply this new thinking may be in the early stages of construction, designated as the MEC coordination period. It is this point in time that the design documents are substantially complete and field coordination by the trade contractors is being completed, prior to equipment and system distribution being installed. It is also at this point in time that commissioning of the record drawings can result in capturing specific layers that will contribute to the next 40 years of facility management.
Some operation and maintenance layers that stand out as basics to world-class facility management environment may be:
Certainly these CAD-layered documents are just the tip of the iceberg for tools that contribute to premiere facility management but they are some of the important issues of today that affect buildings, management of these buildings, and optimizing the useful service life of the building and its infrastructure.
It is already common practice to draw on today's CAD documents for real estate and planning and, through computer technology, it is now possible to link facility management CAD layers to computerized maintenance operation and maintenance (a subject for another time).
In next month's issue, we will share with you our notes taken from a series of roundtable sessions addressing CAD layering for facility management. In this next session will be the thoughts, ideas, and recommendations of facility managers for operation, energy, deferred maintenance, and capital projects, as well as the design community and construction management community.
SummaryThe building industry has made great strides in CAD drawing applications over the past 15 to 20 years. We have evolved from the prehistoric days of drafting, straightedges, and mechanical drawing pencils to CAD documents. At the same time, we can't rest on our laurels. There is more to learn, more to consider, and more to implement. Designers and builders have become proficient at CAD to a point, but it is just the tip of the iceberg when realizing what potential remains to be achieved.
In parallel with this edict to do better, building owners need to also step up and be heard, contribute, and apply CAD documents. They need to express their facility management criteria so that architects, engineers, and construction managers can provide better, more useful CAD documents. In addressing CAD 101 above, we have just touched on yesterday's basis. Tomorrow is a new day with new computerized challenges. ES
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