Within the past decade,
computer software has successfully applied cost-and-time formulas to
manufactured products. This business-oriented approach is fine for
factory-made widgets, but buildings are one-of-a-kind creations,
pieced together in the field under varying conditions and from many
thousands of parts and raw materials. Letting time and budget drive
project delivery means ignoring these variables-and the many
opportunities that come with them.
architecture, engineering, and construction (AEC) industry has its
own set of software vendors who understand the complexities of the
process and are finding ways to connect all the elements of a
project. Doing this successfully, however, means that AEC vendors
must find a method to integrate the data contained in the different
building models that each discipline develops. Allowing engineering
software to communicate with the programs used by electricians,
interior designers, and, of course, architects, would streamline the
construction process. But making these links is not so easy.
From basic CAD to the most sophisticated
construction scheduling system, all software must achieve one basic
goal: to form a bridge between mathematical coding-the language that
computers read-and the characters and pictures that humans can see
and understand. When software developers translate descriptions of
the real world into mathematical code, they call that process
"modeling." The use of this term by computer scientists confuses
architects, who are accustomed to thinking of models as chipboard
and foam-core replicas.
software that produces 2-D drawings is actually a model of the
drafting process. Advanced 3-D CAD software creates what some
vendors call a "virtual building." To the extent that such virtual
buildings include mathematical descriptions of a building's geometry
and parts, they do correspond to the physical scale models with
which architects are familiar. Computer models of buildings,
however, also can include the attributes of a building's components,
like the density of the concrete or the fire rating of the
Other kinds of
design and construction software also rely on models, or
representations of real-world objects. Specifications software, for
example, defines the composition and quality of the parts of a
building and often includes descriptions of how to assemble those
parts. Estimating software uses mathematical models of the
relationships among materials, sizes, quantities, and unit prices.
Scheduling software combines representations of material, equipment,
and labor resources into time-based models that represent the
sequence of design and construction events.
software models of the same building should, ideally, be capable of
communicating freely with each other. But, in most cases, they
software packages differ at many levels, including how they name,
subdivide, and classify building parts; the ways they organize the
attributes of those parts; and their methods for linking parts and
attributes. They also differ in the techniques they use to represent
parts and attributes. The consequences of all this variation include
lost or duplicated information, inaccurately transferred or
converted files, and multiple databases of redundant information
(the digital equivalent of two partners' Rolodexes containing
different phone numbers for the same client). Plus, much time and
effort are wasted in checking these possible sources of error.
benefit if these communication problems were eliminated. Architects
and engineers could incorporate better cost and schedule information
into early design stages, sparing themselves some of the agonies of
redesign. Those involved in the construction phase would enjoy
faster project documentation and smoother workflow. Building owners
and operators would benefit from more predictable time and cost
estimates and would get a useful set of "as-builts," along with
other project information, when the job is done.
Given the potential benefits, it's surprising
that so little has been accomplished in linking design information
software to costs and schedules-though it is not for lack of trying.
Just about every building-product trade association has a
classification scheme. In the U.S., most classifications fit within
the Construction Specification Institute's Masterformat or the ASTM
standard Uniformat II (for classifying assemblies like slabs or
interior partitions). Other countries, including Germany, Japan, and
Brazil, have their own classification systems, as well.
vendors have not, as yet, been able to build on these systems.
Traditional data-linking tools, like file-conversion programs, are
not general enough for the multiple linkages that software vendors
As an interim
measure, vendors of some of the most widely used software have
attempted to forge direct links to one another. Some of these links
rely on common file conversions or translations. Others rely on an
application programming interface-one vendor publishes a set of
software "hooks" to which other vendors write special connection
routines that move data between the two packages. But these are
still program-specific links that are only valid between specific
Fischer and his colleagues and students at Stanford University's
Center for Integrated Facility Engineering (CIFE) are pioneers in
finding ways to link disparate software programs. Fischer has found
ways to make multiple off-the-shelf software packages communicate
using an actual design and construction project-a biopharmaceutical
manufacturing facility in Menlo Park, Calif., designed by Flad &
Associates, based in Madison, Wis.
linked the building model, created in AutoCAD Release 14 and the
ArchT architectural CAD add-on package (now distributed by
EaglePoint), to Timberline Precision Estimating software. This
eliminated many time-consuming manual steps in quantity take-offs
and definition of work packages. A construction schedule from
Microsoft Project was linked to the AutoCAD/ArchT model through
Jacobus Technology's Schedule Simulator to build a virtual version
of the building and identify the most expeditious construction
staging. This yielded an informative kind of 4-D CAD (3-D plus
contractor reported that the cost estimates that were produced came
within 5 percent of those prepared by manual methods, but were
completed 25 to 50 percent faster. The schedules that the CIFE
demonstration generated uncovered conflicts that might not have been
detected otherwise. While Fischer's work [see Digital Architect,
August 1999, page 39] provides insight into the interplay of
multiple software packages on a real project, it is still based on
semicustom interfaces among compatible programs.
Several groups, including CIFE, are now working on
comprehensive systems that allow any design or construction software
to operate compatibly. The best known of these groups is the
International Alliance for Interoperability (IAI), launched in 1995
by software vendors, building owners, and design and construction
firms. IAI is developing industry foundation classes (IFCs) that
standardize software objects that correspond to the physical objects
in actual buildings, such as wall assemblies, doors, and windows.
Because IFCs are backed by the descriptions and attributes of each
building object that they represent, they can be accessed by any IAI
member with IFCs incorporated into their software.
But until IFCs
are more widespread, many software developers offer their own
proprietary pairings. For example, builder-oriented CAD programs
like SoftPlan have complete bill-of-materials capabilities built in.
Graphisoft's ArchiCAD has its own "object" language, complete with
links to WinEstimator's WinEst estimating program. DATACAD LLC's
eponymous CAD software now bundles the Estimator for Windows program
from CMS Estimating. Specifications software vendor ARCOM
(MasterSpec), scheduling software vendor Primavera Systems (Project
Planner), and cost database provider R.S. Means (CostWorks) have
announced plans to link to each other and to Bentley Systems'
TriForma CAD software.
How the Web
Any discussion of how disparate software programs
will communicate must take into account the impact of the Web. An
efficient tool for locating and viewing almost any kind of data,
regardless of the software that created it, the Web may indeed make
it easier for designers and other members of the AEC team to
language of the Web is HyperText Markup Language (ASPL). A newer Web
language called XML, or eXtensible Markup Language, has features
that ASPL does not have, like the ability to describe and classify
the data content-not just the appearance-of a Web page.
companies, including AEC, will benefit from the data exchange
possibilities XML offers. The McGraw-Hill Construction Information Group (which
publishes Record), Primavera, and Bentley have joined with
more than 130 other industry leaders worldwide to form the aecXML
Project. The goal is to develop a framework for XML specific to the
building and design industry.
percentage of overlap between aecXML advocates and IAI members means
that the two will likely develop a supportive relationship-perhaps
with aecXML serving as the Internet transporter for the IFCs.
Regardless, emerging linkages among cost, time, and architecture
will enable buildings in the near future to go up faster and more
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