Although computer-aided design is widely used inthe architecture-engineering-construction (AEC)

industry, the exchange of information is still largely amanual process, where 2D paper drawings arereviewed to identify conflicts. Obviously, this processis time consuming and inefficient —not only do manyconflicts go undetected but it’s nearly impossible toquickly determine how design changes will affect theproject’s cost and schedule. Thus, an average projectwill lose 8 to 15 percent of labor costs due to mistakesthat cause change orders, delays, and rework.

Project management tools also have limitations. Sincethey use critical path method schedules, such tools don’tshow the three dimensions of space and the fourthdimension of time, making it difficult to visualize andcommunicate the schedule and analyze the sequence ofconstruction. Cost estimating is another mostly manu-al process that increases a project’s time and decreasesits accuracy. Software that links design componentswith a cost database and scheduler could overcomethese problems.

Enter 4DCAD technology, which in its simplest formlinks 3D models to schedules. More advanced versionslink costs and other data. Instead of just reviewing print-ed flow diagrams, users can visualize the constructionsequence as a movie or animation. This avoids conflictsin scheduling and resolves safety issues (such as erect-ing steel over where people work) before actual con-struction begins.

The outcome is increased productivity and decreasedwaste on job sites. Research at Stanford University esti-mated that 4DCAD helps avoid up to 45 percent ofchange costs, leading to a minimum of 4 to 6 percentoverall project cost savings. Since construction projectscan cost billions of dollars, these savings become quitesignificant. Another major benefit of 4DCAD is improvedcommunication between all participants involved withthe designing and scheduling of a construction project.

Challenges and limitationsDespite these benefits, one of the largest barriers to

implementation (at least in the conventional AEC indus-try) is that 4DCAD technology requires engineeringdesigns as 3D models, something currently uncommon.From 75 to 80 percent of a 4D model’s cost involves cre-ation of the underlying 3D model. When the designteam works in 3D, that cost becomes a project benefit.Model costs on large projects might run as low as one-

half a percent of the project budget, yet be returned 50to 100 times over in project savings. However, if projectparticipants don’t clearly establish a 4D model’s scopeand purpose and level of detail prior to its modeling, thecost-benefit ratio decreases.

In the cases of processing, power, and offshoreplants—which are much larger projects than the typi-cal AEC project—most projects’ conceptual and detaileddesign and engineering phases produce a 3D model. Forthese projects, the owner-operator generally becomesthe biggest obstacle to 4DCAD technology because ofthe desire to minimize costs in each project phase. Theowner subcontracts each phase to the lowest biddingfirm, and thus data created during each phase is rarelypassed electronically to the next phase.

Another problem is that 3D models need to accom-modate the 4D modeling process. 4D modeling requiressignificant project scope and schedule information,which might not be available. The better the schedulethe easier it is to build a 4D model. The 3D modelsmight be inconsistent in geometry or schedule data,lack data in some areas, be too data heavy in others, orlack enough detail. The geometry definition might con-flict with the schedule, making it difficult to link thetwo. However, providing a software tool to map con-struction organization of the facility to design organi-zation can avoid these problems.

Current commercial systemsAlthough 4D modeling efforts might have begun as

early as 1973, it was not until 1984 that visual con-struction simulation software became commerciallyavailable with the introduction of Construction SystemsAssociates’ PM-Vision. In 1986 Bechtel developed a 3Danimated design review tool called Walkthru for SiliconGraphics workstations, which they later ported to thePC. Jacobus Technology, established in 1991 by formerBechtel employees, developed an interface betweenWalkthru and a CAD system; later they integratedWalkthru with Primaver’s P3 scheduling program.Jacobus marketed this system as the ConstructionSimulation Toolkit, and further work led to the devel-opment of a real-time 3D visualization system calledNavigator. (Bentley Systems acquired Jacobus in 1997.)

During the development of Navigator, StanfordUniversity’s Center for Integrated Facility Engineeringapplied the toolkit to build a 4D model for the San MateoCounty Health Center, the first application involving a

Laurel M.Sheppard

Virtual Building for Construction Projects ____________

ApplicationsEditor: Mike Potelhttp://www.wildcrest.com

6 January/February 2004 Published by the IEEE Computer Society 0272-1716/04/$20.00 © 2004 IEEE

nonindustrial facility. Around this time, BentleySystems’ Schedule Simulator and Intergraph’s ScheduleReview came on the market. These programs had twomajor limitations: a new 4D model was necessary forevery new situation or for different levels of detail, andit was not possible to make changes to the 4D model andsimultaneously update the 3D model and the schedule.

Bentley and Intergraph have continued to improvetheir products to address these issues. Bentley mergedtheir Schedule Simulator with Navigator, which visuallysimulates the construction process by integrating detailed3D models with critical scheduling and planning infor-mation. The software easily generates simulations of con-struction schedules, heavy lifts, material handling,equipment placement, and operations/maintenanceactivities, providing a clear understanding of objectmotions and potential clashes in the area of activity.

Sinclair Knight Merz (SKM), a global consulting firmin Australia, implemented Navigator during its capaci-ty expansion project for an iron ore processing andexport facility in Port Hedland, western Australia. Thecompany chose Bentley Navigator because of its func-tionality; ease of use, implementation, and setup; lowadministration overheads; and open object architecture,according to Trevor Black, group CAD manager for SKM.Navigator provided a means to take data from multiplesources, view and report from a consolidated model,and increase interoperability between project partners.

Navigator reduced variations caused by misinterpre-tation of scope and documentation. SKM also walkedmaintenance crews through the project’s car dumper (amechanical device that unloads freight cars) prior to theletting of contracts. Their input regarding maintenanceaccess and other related issues resulted in some designchanges. This led to large savings in rework or post-pro-ject modifications to the plant. The company carried outa hazardous operations review of the car dumper usingthe model in Figure 1. This resulted in a 50 percent sav-ings in time, when converted to cost savings that actu-ally covered the cost of the software.

SKM made the models available onsite to construc-tion contractors. They constructed many of the transfertowers around existing conveyors whose operationaldowntime had to be kept to a minimum. This requiredcomplex construction sequences that SKM exploredusing the simulation software (see Figure 2).

Intergraph Process, Power & Offshore has exploredconstruction visualization for the last 5 years of its 20-year history in creating 3D visualization software. ItsSmartPlant Review is a Windows-based visualizationsoftware that can handle 3D models ranging from 3 toover 300 Mbytes. The tool is integrated with Intergraph’sPlant Design System. SmartPlant Review’s modular for-mat lets companies add features only when needed.These include modules for construction, simulation andvisual effects, collaboration, and onsite drawing gener-ation. The collision detection function displays objectsthat might collide in a defined movement path, such asduring equipment installation or removal of equipmentfor maintenance (see Figure 3).

Westinghouse Electric used SmartPlant Review andPlant Design System to visualize the construction sched-

IEEE Computer Graphics and Applications 7

1 The car dumper was a challenging engineering exercise as the dumper wasaround 40 meters deep and the ground water table was around 2 meters.

2 Sinclair Knight Merz used the transfer station model for a constructionsimulation to highlight construction’s complex nature. They built the trans-fer towers around existing conveyors (shown).

3 As a horizontal vessel is lowered and rotated intoplace during a construction sequencing review, a flangecollides with a beam. SmartPlant Review has highlight-ed the steel beam in transparent red.

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ule and activities of its AP600—a 600-MW advancedpressurized light-water reactor plant—and eliminatedthree to five months from the schedule through logicand design changes alone. Westinghouse determinedthat each day of construction removed from the sched-ule was worth at least 70,000 dollars to the owner incost avoidance. Just one change found using this toolallowed Westinghouse to take six weeks off the criticalpath, reducing costs by more than 2 million dollars.Figure 4 shows an overview view of the model.

This change involved realigning the schedule to putrebar for the containment internal structure into thelower containment vessel head before its placement onthe site foundation. Initially this placement was sched-uled to occur onsite, in the hole, after placement of thecontainment vessel, which caused six weeks of rebarwork on the critical path. Westinghouse only discoveredthis when viewing the 4D construction, not in the stan-dard review of the schedule. Redesigning some compo-nent foundations also allowed for quicker construction.

The size and complexity of the 3D model requiredWestinghouse to fine-tune its use of SmartPlant Review.“First, the model was broken into separate buildings,”explains Jill Clelland, information management lead of

Passive Plant Projects & Development. “Second, for viewmanipulation, the view cone was shortened. This is thefeature that tracks all of the elements that will beredrawn.” In other words, a view cone determines whatthe application’s eyes can see, such as limiting the viewto only the first 50 feet from the eye point, and only a40-degree field of view. By limiting this cone view, feweritems are processed.

More recently, other companies have entered the4DCAD market, including Balfour Technologies,Common Point, and Reality Capture Technologies. Allcontinue to improve their softwares’ capabilities, whichvary in cost and functionality. As these improvementscontinue and costs reduce, usage should increase.

Balfour TechnologiesBalfour Technologies’ fourDviz technology grew out

of a joint collaboration between Balfour Computer Sys-tems and Infinity Technologies (Balfour Technologies’predecessor companies). The software was originallyan in-house tool for producing 4D visual deliverablesfor transportation consulting contracts. It’s based onflight simulation technology and company cofounderRobert Balfour’s doctoral research in temporal visual-ization and computer-generated holography fueled fur-ther development of this tool.

After its launch in 2001, the company licensedfourDviz software to several clients. Boston’s LoganAirport Modernization Program first used fourDviz (nowavailable as fourDscape) onsite as a construction plan-ning and management tool (see Figure 5). Simulationscreated in conjunction with Auburn University for a pro-ject planned for Huntsville International Airport inAlabama later employed the software.

Balfour and Infinity merged in 1999 to form BalfourTechnologies. In 2003 Balfour announced fourDscape,which incorporates a desktop browser that lets usersvisually integrate and analyze multidimensional dataflows in a collaborative environment. FourDscape usersinteract with 3D visual models driven by datasets oftime-dependent information, with complete control ofstepping forward or backward in time to identify causeand effect relationships between the visualized datasets.

Using fourDscape the user opens a hyperlink to a URLfor a 4D portal server, gaining access to 3D models anddatasets integrated into a 4D landscape. Using themouse, the user interacts with the 4D scene, using VCR-like buttons (pause, play, stop, fast forward, rewind) onthe toolbar to move in the four dimensions of time andspace. A unique collaborative feature in fourDscape isthe ability to handoff a local fourDscape GUI to a remoteuser connected to the same 4D portal.

Previous fourDscape application areas include trans-portation planning, engineering and intermodal facili-ties logistics, and design and construction management.Demonstration projects have included warehouse oper-ations analysis and real estate management. A new pro-ject is scheduled for a New York Department of PublicWorks and Health study. However, Balfour’s technolo-gy is generally application independent (just like a Webbrowser) and can visualize almost any time-dependentdata that needs analysis.

Applications

8 January/February 2004

4 Overviewview of theAP600 modeldeveloped withSmartPlantReview.

5 Constructionphasing atBoston’s LoganAirport usingfourDscape.Color codingshows construc-tion phases,enabling man-agers to foreseescheduleconflicts.

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IBM’s Transims, a transportation modeling and fore-casting software package, uses fourDscape for visualiz-ing results of simulations including vehicular traffic,emissions, and transportation infrastructure perfor-mance data. fourDscape was selected because it met thecompany’s requirements regarding performance andcost. “We needed a 4D visualization package capable ofhandling the tremendous size of datasets generated byTransims,” explains Jason Dulnev, IBM BusinessConsulting Services’ principal consultant and theTransims project’s technical manager. “For example, asingle traffic dataset for a medium-size city can easilyexceed 1 Gbyte in size.”

To integrate fourDscape with Transims, IBM adaptedthe product to access Transims-specific file formats, andsome additional functionality was added. ThefourDscape GUI was also streamlined to optimize thenumber of steps needed to activate various capabilities.To date there have been two implementations ofTransims models—in Blacksburg, Virginia and Portland,Oregon. Figure 6 illustrates transportation forecastingfor the latter.

Common PointCommon Point’s Common Point 4D is a tool based on

a middleware platform that targets the entire design,construction, facility operations, and capital asset man-agement market. It originated from joint researchbetween Walt Disney Imagineering and StanfordUniversity’s Center for Integrated Facility Engineering.The tool lets design and construction professionalsreview and reorganize the 3D model and correspond-ing construction schedule at several levels of detail andin several integrated computing environments, such asdesktop, Web, and VR (using a CAVE).

A hierarchical approach allows links between any levelof detail of the 3D model and construction schedule.

Users can easily group product components into con-struction zones, enabling customization of the content,view, and level of detail for any visualization. Users canalso efficiently update a 4D model because they canmake changes at any level. The latest version has anenhanced set of CAD adapters and integration tools. Itprovides Graphisoft’s ArchiCAD, AutoDesk’s Architec-tural Desktop (ADT), and Bentley’s Microstation withthe ability to give full attribute and type extraction fromADT objects and the ability to dynamically and remote-ly link to CAD files, automating the update and importprocess at a file or folder level.

The first application of Common Point’s 4D softwarewas the strategic planning of the construction sequencefor Paradise Pier within Disney’s California Adventure.Walt Disney Imagineering used the software to devel-op and review track erection sequence options. Thissequence had to assure that the ride test and adjust pro-cedures were completed to support opening day, threeyears from this planning stage. The final constructionsequence needed to maximize productivity for con-struction and erection of the lagoon and the six attrac-tions placed under, within, and directly adjacent to thecoaster track.

The launch portion of the track lies just above thelagoon’s surface. Therefore, Walt Disney Imagineeringhad to fill the lagoon prior to the test and adjust proce-dures. In addition to the launch and other portions of thecoaster track, the footprints of three independent attrac-tions lay within the lagoon. To effectively communicatethe erection options including material lay-down areasand crane pads, the 4D model also provided erectionsequences for two other attractions (see Figure 7).

Walt Disney Imagineering successfully used the 4Dtool to determine the optimum contractual sequence ofthe work, which was divided into two stages. The firststage included all deep foundations for the coaster, arough-graded lagoon, and foundations within thelagoon. This stage was bid and constructed concurrentlywith the completion of design documentation for the

IEEE Computer Graphics and Applications 9

6 Transportation forecasting in downtown Portland,Oregon using Transims and fourDscape. Visualizingsimulated traffic patterns enables effective planning,yielding improved transportation infrastructures forpredicted traffic volumes.

7 4D snapshots of Common Point 4D, supporting sequence and develop-ment of project milestones for Paradise Pier in Disney’s California Adventureby Walt Disney Imagineering.

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balance of the work. The second stage was bid at moreor less substantial completion of the first stage and bidresults were within +/−2.5 percent of the budget.

Using VR reduced the time needed to resolve con-struction problems from several hours to less than 10minutes. The scheduler also considered 20 differentdesign and schedule scenarios over a two-week period.Communication became more effective as well: theowner’s project management team made clear therestricted lay-down space and access routes to the gen-eral contractors, who in turn used the 4D model to showtheir subcontractors the project’s challenges.

In another application of Common Point 4D, DPRConstruction used 4D models to help an owner visualizethe future and demonstrate to hospital administrators atBanner Health Good Samaritan Hospital in Phoenix,Arizona that DPR had the best approach for maintaining24/7 operation of critical care facilities. Administratorssubsequently used the 4D models to educate physiciansand staff about what would happen during each con-struction stage. The improved communication betweenhospital and construction staff helped minimize the risksto the hospital operations. For example, the 4D modelalerted the hospital to the need to change the medivachelicopter’s flight plan during steel erection in a timelymanner so that the necessary FAA approvals could beobtained (see Figure 8).

Applications of Common Point 4D since 1998 haveincluded more than 70 projects ranging from large-pro-ject and campus strategic planning, construction andfacility operations coordination, overall design and con-struction coordination, site logistics and constructionmethods improvement, and scope-of-work planning.Additionally, students at more than 15 universities usethe software to support research and development anddesign and construction management courses.

Construction Systems AssociatesIn 1984 CSA developed PM-Vision, an application that

used 3D CAD to depict the sequence of a constructionproject. The company marketed the software until 1989,when CSA realized that practical application of this tech-nology would be too expensive. Around 1995, CSAexpanded the PM-Vision module considerably, addingnew functions and a new user interface. “Acceptance of

this technology is considerably high-er than it was 20 years ago,” saysAmadeus Burger, CSA president.

PM-Vision integrates a 3D CADplant model with a project schedule,allowing visual representation ofthis schedule, as well as use of thedatabase to support the presenta-tion of a cost-effective schedule andanalysis of sequence and resourcesfor implementation. The software isbased on CSA’s master model tech-nology, which is a large-scale facili-ty database integrated from avariety of sources and formats,including schematics, text, and doc-uments. The model reorganizes the

plant by construction zones and type of systems, forexample electrical or plumbing. The user can also applydifferent organizational structures (engineering versusconstruction) to the model.

Objects in the model are parametric objects. Eachobject is a mathematical representation of an object typethat resides in the master database that contains theobject’s physical data and a data parameter series relat-ing to the object’s characteristics. As an object is placedin the model, the software draws data from the masterdatabase and any imported data linked to the object.Users can query every object in the model for availabledata and linked documents and reference information.

PM-Vision transfers schedule activities from the sched-uler along with activity attributes to the software’s data-base. Attributes include location codes, disciplines, andresponsibility codes. Users can extract partial schedulesto create a specific review schedule for a certain sub-contractor, discipline, or building. The database can alsocontain multiple versions of schedules to assess impactof various assumptions and changes. The model data-base has no size and complexity limit. The user can reor-ganize the data to match the schedule. Once the userdetermines a schedule they have a wide variety of dis-play options, including schematic diagrams and graph-ical displays of work content for a specific activity.

Westinghouse Electric Nuclear Systems is one of anumber of companies that have used PM-Vision. For thiscompany, the software saved 15 percent in constructiontime after modeling a nuclear power plant. IntelCorporation also used the software for its D1D fab pro-ject located in Hillsboro, Oregon (see Figure 9). Thepilot’s scope included all of the civil, structural, archi-tectural, process, and mechanical requirements for fourbuildings, totaling over 1 million square feet.

To save time and effort, rather than redraft the 2Ddesign in 3D, Intel converted its model into three dimen-sions. Although this conversion was a significant portionof the pilot’s cost—around 75 percent—it only took severalweeks. An interface module converted the project modelinto a tree structure, allowing quick and easy access.

Automatic interference checking reports, highlight-ing conflicts between systems and assemblies, was oneof the most useful aspects of the integrated modelingapproach. Resolving these conflicts resulted in signifi-

Applications

10 January/February 2004

8 DPRConstructionused 4D modelsto coordinatehospital opera-tions withconstruction;this 4D modelsnapshot showsthe steel erec-tion next to themedivac heli-copter flightpath.

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cant cost savings. Out of a total savings of 2.45 milliondollars for the entire project, Intel attributed about 50percent to resolving schedule conflicts. The process alsorevealed design problems; for instance, Intel changedlight fixture locations based on light pattern blockingidentified in the model.

Reality Capture TechnologiesSimilar to CSA’s PM-Vision, Reality Capture’s

ConstructSim is based on a virtual plant model anddynamically integrates 3D CAD, engineering systems,project schedules, project control databases, materialsmanagement systems, as-built data, and other digitalinformation. The plant model links applications anddatabases into a distributed network and allows use ofengineering design data for start-up, operations, andmaintenance phases of a facility’s life cycle. An XMLframework provides interfacing with project controlsand material management systems.

ConstructSim automatically organizes the engineer-ing design model into constructible elements so that thevirtual model represents the way the facility is built, notjust the way it is designed. Model components are iso-lated based on process systems, construction zones, orother user-defined attributes, and automatically createlogical group detailed tasks. After construction zonesare defined, the engineering design model is automati-cally organized according to craft (pipe, mechanical,civil) and zones. Users can then quickly query and dis-play model components. ConstructSim also incorpo-rates additional intelligence such as process flow modelsto enable advanced features such as following a pipeline.

As the tasks are detailed, the tool generates a 4D con-struction schedule simulation by automatically associ-ating each detailed task with the respective scheduleactivity identification. The software also generatesdetailed weekly work packages (see Figure 10), followedby a bill of materials that is synchronized with the mate-rials management system. As tasks are completed,ConstructSim synchronizes with the project controlssystem to update task status in the model and providethe ability to visually monitor detailed project progresswithin the virtual model (see Figure 11, next page).

One major difference between ConstructSim andother software is its ability to automatically update thevirtual plant model. Other systems require manualupdating, which can be a resource drain on users.ConstructSim is also user friendly due to its joystick-based operation.

One expansion project that implemented Construct-Sim saw the elimination of four to five project personneland the reduction of total installed construction costsby more than 4 percent. This project required adaptersto enable the dynamic integration of a 3D CAD systemand project schedule as well as the constructor’s pro-prietary materials management system and project con-trol applications.

This project mainly used ConstructSim as a tool forinteractive planning and field execution of weekly workpackages for piping. To support the interactive weeklywork planning, ConstructSim automatically produceda detailed level-4 task plan (a schedule that details the

IEEE Computer Graphics and Applications 11

9 Simulation of a construction schedule for a portion of a large-scale semi-conductor facility. Yellow indicates activity in progress, red means critical-path activity, green signifies activity completed. After the activity hascompleted processing, the geometry changes to its original color.

10 ConstructSim displays work package creation where users plans the idealgrouping of materials into work packages weeks before mobilizing for theseactivities in the field. Colors within the picture represent different processsystems except for the white spool, which means it’s selected for addition tothe work package.

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tasks associated with work packages) of over 25,000steps for piping, based upon a seed level-1 (milestone)master schedule of approximately 100 activity items.

The prioritization of procurement and the ability tomonitor the delivery of spools onsite paid off early in theproject. As the project team mobilized in the field, pipespools began to arrive late, and the majority of pipespools that did arrive were those for the upper levels ofthe structure that was to be erected, not the lower levelswhere the pipe team could gain access for installation.The team could easily determine the areas where instal-lation could begin based on the availability of materials.

In addition, the team used priority information forfabrication sequencing to help expedite spool deliveryin the construction areas so that the project team couldbegin pipe installation. ConstructSim workstations inthe field supported engineering for the constructioncrews (reducing requests for information), and those inthe project management offices monitored task progress

on a daily basis and identified conflicts and issues beforethey became problems in the field.

Future outlookAs advancements continue, 4DCAD will eventually

become the standard for all phases of facility design,engineering, and life-cycle engineering regarding oper-ations, maintenance, and retrofit. It will also expand toe-commerce to improve procurement of materials andservices. However, a shared project model will have tobe developed, as well as reliable electronic informationexchange standards. Faster information exchange willkeep data up to date and help identify discrepancies.

A move to more open platforms will also improve theability to move data intelligently throughout the lifecycle and between project partners. In addition, devel-oping shared models requires a change in mindset toview facilities design, construction, and operations in aholistic or integrated manner instead of as separate enti-ties. In turn, all principals involved must work moreclosely together.

According to Robert Christian, a senior manager ofbusiness development for design systems at IntergraphProcess, Power & Offshore, “The 4D tool of the immi-nent future is one that combines data and workflowmanagement and 3D and 2D design, integrated multi-discipline engineering tools in a single environment thatdoes not rely on now-outmoded CAD packages.” �

AcknowledgmentsI thank the following people for their assistance with

this article: Robert Balfour (bob@BAL4.com), BalfourTechnologies; Christopher Rogers (Christopher.Rogers@bentley.com), Bentley Systems; Martin Fischer, Centerfor Integrated Facility Engineering, Stanford University(fischer@stanford.edu); Kathleen Liston (kathleen@commonpointinc.com), Common Point; AmadeusBurger (amadeus@csaatl.com), Construction SystemsAssociates; Tom Greer (TPGreer@ingr.com) and RobertChristian, Intergraph Process, Power & Offshore; EricCrivella (eric.crivella@reality-capture.com), RealityCapture Technologies; and Jill Clelland (clellaja@west-inghouse.com), Westinghouse Electric.

Readers may contact Laurel Sheppard at lashpubs@infinet.net.

Contact editor Mike Potel at potel@wildcrest.com.

Applications

12 January/February 2004

Related Articles

� B. Fröhlich et al., “Collaborative ProductionModeling and Planning,” IEEE ComputerGraphics and Applications, vol. 17, no. 4,1997, pp. 13-15.

� Technical reports and working paperspublished by the Center for IntegratedFacility Engineering can be obtained fromCIFE’s Web site; http://cife.stanford.edu/Publications/index.html.

Links To Learn More

� Balfour Technologies (http://www.BAL4.com/) � Bentley Systems (http://www.bentley.com/products/navigator)� Center for Integrated Facility Engineering, Stanford University

(http://cife.stanford.edu/)� Common Point (http://www.commonpointinc.com/)� Construction Systems Associates (http://www.csaatl.com/

gallerymovies.shtml)� Intergraph (http://ppo.intergraph.com/visualization)� Reality Capture (http://www.reality-capture.com/)

11 ConstructSim displays construction status review where users visuallymonitor construction execution status and colorizes the model based onwork completed and needing to be completed. Colors represent items, asfollows: gray for project piping, yellow for unloaded pipe, green for fabri-cated pipe, blue for installed pipe, cyan for tested pipe, and purple forrestored pipe.

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