2 Assignments - PAPER – Construction Business – Lean Construction– CONSTRUCTION PROJECT MANAGEMENT

also provide a useful visual description to the designer/ contractor. As the technology has improved, the 3-D models have been extended into 4-D (3-D + time representation), where construction schedules are integrated with 3-D displays to simulate the progress of a construction project. 111e 4-D system provides improved work sequencing. Spatial conflicts between different trades are avoided and resource utilization is maximized through visual monitoring. s-D improves the accuracy of virtual estimates.

l \r.

E!gure s.1 Use of 30 visuali.zation in design and construction ./

111e basic technology required for animated 3-D consists of high performance personal computers or workstations connected overla network. Additionally a video studio is needed for digital editing and animation recording with graphic cards. The applications extend fro m project development to the facility operation and management stage. All project participants can increase the quality of both the design and construction process. Moreover, instead of having to browse through pages of documents, users can navigate through a model and then through simple mouse clicks, access the relevant information.

Virtual design studios and concep.1

Virtual design studios allow designers and experts from different locations to interact using audio and video conferencing. Virtual studios allow designers to discuss matters related to design or construction without leaving their offices. 111ey can share the same screen and the same program thereby entering the same virtual reality s~<ie. 111e technology includes high-speed computers or workstations with fast Internet access. 111e main benefit lies i n the fact that experts and designers fro m any location and at any time can discuss a design issue and propose an immediate solution. ...._,/

0....,,, Building information modeling ~<:a

Building information modeling (BIM) is the process of generating and managing buij,~ng data during its life cycle. It is also a tool as well as a process, and increases productivity and accuracy in the design and construction of buildings. ,,, .,

.. BIM uses three-dimensional, dynamic building modeling software and,. operates in real-time. It supports the

continuous and immediate availability of project design scope, scheduI , and cost information that is high quality, reliable, integrated, and fully coordinated. r.,J

111e process produces the building information model, also lqjown as the BIM, which encompasses building geometry, spatial relationships, geographic information, and qua1 tities and properties of building components. 111ough it is not itself a technology, it is supported to varying degrees by different technologies. 111e BIM is a data-rich, object-oriented, intelligent and parametric digital representation of a facility, fro m which views and data can be extracted and analyzed to generate information that can be used to make decisions and to improve the process of delivering a constructed facility (AGC 2005).

111e American Institute of Architects (AJA) has defined BIM as "a model-based technology linked with a database of project information." A BIM carries all information related to a facility, including its physical and functional characteristics and project life cycle data, in a series of "smart objects." For example, an air conditioning unit within a BIM would also contain data about its supplier, operation, and maintenance procedures; flow rates; and clearance requirements.

History_gf_.::B~ 111e term BIM appears to have been adopted by Autode;j,;/o describe "3-D, object-oriented, AEC-specific CAD." 111is medium was rich in architectmal information and distinguished from the traditional 2-D drawing. Professor Charles M. Eastman at Georgia Institute of Technology has done extensive work on the process starting in the 1970s under the heading of a building product model. He has described BIM and documented its application in several publications (Eastman et al. 2008). Jerry Laiserin is said to have popularized the term BIM as a digital representation of the building process to facilitate exchange and interoperability of information in digital for mat. In 1987, Graphisoft's ArchiCAD first implemented BIM under tl1e virtual building concept.

').parametric building modeling technology.

111is technology curre~tly provides the highest level of BIM with the least amount of effort - it is far more sophisticated than Cl\D and Object CAD technology, and requires a completely different mindset in its users. It is an integrated syste1? that embodies geometry and data representation and the relationships between different elements of the model are user-defined. In a manner analogous to an electronic spreadsheet, as one element is changed, this change is reflfcted appropriately to all elements of the model. 111is facility makes the design process (and subsequent construction) faster, more cost effective, less prone to errors, and higher quality.

111ere are a number of well-established software titles that have been continually upgraded, such as ArchiCAD by Graphisoft, Bentley Systems, an integrated project model based on a number of related application modules, such as Bentley Architecture, Bentley Structures, and Bentley HVAC.

Nemetschek has been available primarily in Germany and Europe. Autodesk Revit software is based on parametric building modeling technology and is designed specifically for BIM.

It has a central project database that contains representations of all building elements. Design revisions ar;, f' immediately reflected throughout the entire project, and errors are readily detected. A number of software companies have competing products. It has been subjected to many upgrades.

As described by AEC Bytes 2017 (edited by Lachmi Khemlani, Ph.D.), Autodesk's BIM 360 is a unified pfatform connecting project teams and data in real-time, from design through construction, supporting info~med decision- making and leading to more predictable and profitable outcomes. It provides design collaboration ...j

solutions to accelerate project delivery, reduce rework, and improve productivity by enabling teams to securely co- author BIM designs in real-time and streamline deliverable coordination. Autodesk has developed a cloud platform termed Forge, introduced in 2015, to provide program interfaces for cloud-based applications. One of those applications is Lens, a model-based estimating tool developed by JE Dunn Construction Company Inc.

Forge has enabled the addition of several features of Autodesk's BIM 360 platform, such as BIM 360 Glue for model management, BIM 360 Field for managing construction logistics on site, BIM 360 Layout for site positioning, BIM 360 Plan for construction planning, and BIM 360 Docs for document management.

BIM 360 can be enhanced with the power of immersive visualization, that allows users to realistically evaluate and understand a design model by "walking through it" to get a much more accurate understanding of the final product before moving into construction.

Practical apfl.lications of_BIM

A building information model can be used for the following purposes:

• Visualization: 3-D renderings can be readily generated~ • Fabrication/shop drawings: It is easy to generate shop drawings for various building systems, for example,

the sheet metal ductwork shop drawing can be gufcicly produced once the model is complete. • Automated Fabrication: In projects that involve technologically advanced suppliers, data fro m a BIM file can

be used as input to program numerically controlled fabrication equipment. • Code reviews: Fire departments and other officials may use these models for their review of building projects. • Forensic analysis: A building information model can easily be adapted to graphically illustrate potential

failures, leaks, evacuation pla1~d so on. • Facilities management: Facilities management departments can use BIM for renovations, space planning, and

maintenance operations. • Cost estimating: BIM)Software has built-in cost estimating features. Material quantities are automatically

extracted and changed when any changes are made in the model. • Construction sequenci.ng: A building information model can be effectively used to create material ordering,

fabricatio11 antl delivery schedules for all building components. • Conflict, interference and collision detection: Because BIM models are created to scale in 3-D space, all major

system/ can be visually checked for interferences. 111is process can verify that piping does not intersect with steel beams, ducts, or walls.

Building information modeling makes a reliable digital representation of the building available for design decision making, high-quality construction document production, construction planning, performance predictions, and cost estimates. Having the ability to keep information up-to-date and accessible in an integrated digital environment gives architects, engineers, builders, and owners a clear overall vision of their projects, as well as the ability to make faster informed decisions. BIM makes available more design options and alternatives than traditional methods with similar time schedules and budgets. BIM provides two major benefits:

)"

• As important design information is kept in digital for mat, it can be easily updated and shared with all tl1e involved parties. ~

• 111e maintenance of real-time design data in digital for m, using parametric building modeling technology, provides major savings of time and money. 111is leads in turn to an increase in project productivity and quality. ~

BIM represents a major departure fro m the traditional computer-aided drafting method of d!'" ring with vector file - based lines that combine to represent objects. It models the actual parts and pieces being_.used to build a building. While line drawings can be interpreted by people, they cannot be readily interpreted by,1computers. BIM represents object parametrically in 3-D; these objects reconfigure themselves automatically ~hen software instructions are invoked to show different views in accordance with defined rules. As 3-D object~ art'machine-readable, errors can be

"~

avoided at all phases of design and construction in real-time, as opposed ~ th e t ime honored method of post facto drawing review. In fact, design or fabrication work can be reviewed remo_t~Iy through web conferencing tools such as Webex or GoToMeeting.

BIM can be used to demonstrate the entire building life cycle i1~ding the processes of construction and facility operation. Qyantities and shared properties of materials can easily Ile extracted. Scopes of work can be isolated and defined. Systems, assemblies, and sequences are shown in a relative scale with the entire facility or group of facilities.

BIM enables a virtual inform ation model to be handed fro m a design team to the contractor and subcontractors and then to the owner, each adding· their own additional discipline-specific knowledge and tracking of changes to the single model. 111is approach greatly reduces the loss of information that occurs in the transfer of a project fro m one entity to the other.

111ese attributes enable BIM to reduce waste and inefficiency in building design and construction. It has proven to be attractive to a number of both public and private users that are concernecl_a~out managing completed facilities and wish to reduce or avoid the operational shortcomings that plague many suctt"facilities. In particular, the reduction in design errors and construction errors has a major impact on the users' experience. \Vhereas the traditional approach involved producing contract drawings that were subsequently converted to more detailed drawings for shop fabrication purposes, a BIM m odel can readily generate such shop drawings. Furthermore, it provides instructions in machine-readable for m that can be used by fabrication equipment for more cost-effective production and greater accuracy than craft labor. J

BIM addresses a major shortcoming of the desig•l.,2.P construction processes - that of the interoperability of construction documents and information between the various parties to construction projects. 111is lack of interoperability leads to errors, misinterpretations of building system conflicts, and delays as the design and construction process passes tluough different phases. Effectively, the owners' project requirements and the designer's intent are often not fully preserved during the transition. BIM improves interoperability by integrating computer models into project coordination, simu~on and optimization - the information provided by such models is used to generate feedback.

BIM can serve to prevent the information loss associated with handing a project fro m the design team to the construction team and to th~uilding owner/ operator, by allowing each group to add or reference back to all the information they acquire during their period of contribution to the BIM model. By way of an example, a building owner could use BI~l-~o},track down the source of a building problem without leaving a computer terminal. A water valve can be identi~in a location of interest, and checked to see whether it is a likely cause of the observed problem. A system user can readily verify the specific valve size, manufacturer, part number, and any other information that resides in the BIM database.

BIM f_or architects

111e project architects can take advantage of BIM in schematic and detailed design; and construction detailing phases. Following are some of the main benefits of BIM for project designers: (!) Better design by rigorously analyzing digital C models and visual simulations and receiving more valuable input fro m project owners; (2) Early incorporation of J sustainability features in building design to predicts its environmental performance; (3) Better code compliance via visual and analytical checks; (4') Early forensic analysis to graphically assess potential failures, leaks, evacuation pla1~ f' and so forth; and (s) Qyick production of shop or fabrication drawings (Kymmell 2008). '\,,

111e use of BIM in the project planning phase allows project designers to analyze space and under~1d the complexity of space standards and land regulations, which saves time and provide the team with

opportunity of doing more value-added activities (CICRP 2009). Some researchers have investigated the integration of BIM with GIS (Geographical Information Systems) which can aid project planners in selecting appropriate site and conducting project feasibility and marketing studies (Berlo and Laat 2011; Isikdag et al. 2008). 111e architects and engineers can take advantage of BIM applications at different stages of project design namely schematic design (SD), detailed design (DD) and construction detailing (CD). Table 5.1 illustrates specific BIM applications in each stage of project design.

Economic benefits

Studies by Stanford University's Center for Integrated Facilities Engineering (CIFE) based on several major projects attribute several savings to the use of BIM: (CIFE 2007)

• Up to 403 elimination of unbudgeted change, • Cost estimation accuracy within 33, • Up to 803 reduction in time taken to generate a cost estimate, • A savings of up to 103 of the contract value through cla.fu' detections, • Up to 73 reduction in project time, / • An increase in field productivity in the range ~0-303, and • A tenfold or greater reduction in requests for information (RF!s) and change orders.

Benefits of_BIM at each construction P-roject P-hase

Building information modeling supports-'1e continuous and immediate availability of project design scope, schedule, and cost information that is l~igh. quality, reliable, integrated, and fully coordinated. Among the many competitive advantages it confers are:

• Faster delivery speed :resulting in time savings. • Better design j desig·n proposals can be analyzed in detail, using simulation and other evaluation tools to

identify the best solutions. • Lower costs, which represents financial savings. • Btt!er coordination between different disciplines resulting in fewer errors. • Higl1e1· work productivity and quality. • Provides benefits in the design, construction, and management phases.

BIM Benefits i11 the design phase

During the design phase the scope, schedule, and cost of a project have to be carefully balanced (Eigure 5.2). Changes in any of these factors affect the other two. Scope changes directly impact project costs, and are likely to affect the fl' schedule of the project. In tbe traditional approach, designers readily manipulate information relating to spa$ial layouts and building geometry. On the other hand, this work is detached fro m cost and schedule considerations. Cost and schedule information is time-consuming and often difficult to assemble. It is also based on the>"design configuration available, and subsequent design changes may easily invalidate cost and schedule estimates.

Table s.1 An Illustration of Cost and Time Savings via BIM in Hilton A!juarium Project

Schematic Design Detailed Design

• Options Analysis (to compare multiple design • 3D exterior and interior options) models

• Photo Montage (to integrate photo realistic • Walk-through and fly- images of project with its existing conditions) through animations

• Building performance • analyses (e._g. ener~~

_j Construction Detailing

fl' • 4D phasing and

scheduling • Building systems analysis (e.g. clash

detections)

Predesign/ planning phase

' 7

Design phase

' 7 , ;

Construction phase

' 7 ~ ,, " Acceptance phase

' .)

' 7 v

Postcons1ruction/ warranty phase

' .. modeling) • Structural analysis and

design

""" Involve the owner, verifyJthe OPR, ensure

• Shop or fabrication drawings

clarity/completeness. Ensure the appropriateness of the proposed facility design. (Design t he "righf' facility) review BOD developed by design team review scope of equipment and systems

Record design options for evaluat~n support design for constructability provide evaluation of design alternatives cost analysis of altemati es

J Support procurement with accurate quantity take-offs facilitate pref f rication from design information enable j~n-time procurement reduce conflicts between trades/disciplines. e .g ., structural, electrical, HVAC, plumbing, fire protection trac;k construction in real time

Provide vi rtual start up to verify system readiness track/manage documentation of equipment update "as-builts" for record purposes

Track facility condition and performance of equipment, energy usage track tenanVuser changes track warranty issues track life cycle costs

Eigure 5.2 Process fl ow for BIM design and construction sup.P-Qrt

BIM makes design information readily available to all stakeholders that are involved in the design process. 111e design team is empowered to make desired changes in real time without the need to do expensive and time· C consuming coordination and checking by hand. 111e design concept is incorporated in the BIM model - as design work J progresses its evolution is c.aptured in it. Changes are automatically coordinated instead of requiring manual , verification by the design team. 111e near elimination of errors enables the quality of design work and it,s documentation to be greatly im proved. )"'

111e speed of delivering the design and accompanying permit or other documentation is greatly enhanced,~th less individual effort. BIM provides. the design team with a versatile tool for representing

Building information modeling can facilitate the integration of energy level calculations with the design process - the impact of design changes with these energy levels can be examined in real-time. BIM models store multidisciplinary information within one virtual building representation. 111is information includes geometric, semantic, and topological information - building shapes are 3-dimensional and are represented as geometric information. Semantic information defines material properties such as thermal resistance. Topological information relates to the dependencies of the components of the building.

Based on the thermoeconomic concept of energy, exergy analysis relates to the quality of energy and provides a holistic representation of a building. It requires an interaction between the factors that represent geometric, semantic, and topological information. 111e parameters that define this information during the design process can be used for performance calculations. Designers can gauge the impact of design changes by invoking the performance calculations almost in real-time. Adoption of BIM early in the design process facilitates interactivity in the design and performance measurement activities. In the United States, the govemmen 's procurement agency - the General Services Administration requires designers to utilize BIM for construction projects at the outset of the design process (Schlueter and 111esseling 2008).

BIM for green building design 7

111e most effective decisions related to the sustainable design of a facility can be made in the early design and preconstruction stages. Traditional CAD planning environments, however, do not support the possibility of such early decisions (Azhar and Brown 2009). Building p; rformance analyses are typically performed after the architectural design and construction docum ents have been produced. 111is lack of continuous analysis of sustainability in the design process leads to an inefficient process of retroactively modifying the design to achieve a set of performance criteria (Schlueter and 111esseling 2008). In orof.· to assess building performance in the early design and preconstruction phases realistically, access to a comprehensive set of knowledge regarding a building's for m, materials, context, and technical systems are requ~. Because building information modeling (BIM) allows for multi-disciplinary information to be superimposed within one model, it creates an opportunity for sustainability measures and performance analyses to be perfor med throughout the design process (Autodesk 2008; Schlueter and 111esseling 2008).

For example, architects can use a building information model to analyze a building's mass and for m to optimize envelope and balance glazing ratios. Engineers can use this model to reduce energy demands through energy modeling, which uses the 3D model to calculate light reflectance and penetration. Contractors can analyze site conditions, including wetlands and protected habitats, and use the site model to coordinate logistics better to eliminate potential issues. Subcontractors can use BIM technology to reduce waste and combine shipments to further reduce carbon footprints (Hardin 2009). Eigure 5.4 describes the typical flow of information taken into account when conducting performance analyses using a building information model. 111e building information model contains basic information such as building geometry, building materiality, building systems, and internal loads. Based on this information, as well as additional information, which is entered into the performance analyses software, C environmental evaluation of a building can be performed. Such an evaluation could greatly help designers to optimize ., the environmental performance of the building.

BIM can reduce the costs associated with sustainability analyses by making the information required for sustainabls> fl' design, analysis and certificat ion routinely available simply as a by-product of the standard design process . .,mM provides the opportunity to realize numerous benefits throughout the project conception, design, constru~n and post occupancy phases of a building (Azhar et al. 2008). Linking the building information model to energy analysis tools allows for evaluation of energy use during the early design phase. 111is is not possible using traditional 2D tools, which require that a separate energy analysis be performed at the end of the design process.~ reducing the opportunities for the early modifications that could improve the building's energy performance (Azhar et al. 2009) .

.) fl'

~'-:)

~4i~

-.. Building Materiality

Weather Conditions uilding Systems (HVAC)

Thermal Analysis

Lighting,l()aylighting Anatysis

E!gure 5.4 TY.P-ical information flow in BIM-based bui~krformance analY.ses Source: Azhar and Bro\vtl 2009

Internal Loads

Hardin (2009) established three main areas of sustainable design with a direct relationship to BIM. 111ese areas are "material selection and use", "site selection and management" and "systems analysis". In addition, Kriegel and Nies (2008) indicated that BIM can aid in the ,,owing aspects of sustainable design.

I Building orientation (to select the best orientation that results in minimum energy costs), 2 Building massing (to analyze building form and optimize the building envelope), 3 Daylighting analysis, 4 Water harvesting (to reduce water needs in a building), 5 Energy modeling (to reduce energy needs and analyze renewable energy options such as solar energy), and 6 Sustainable maferials {to reduce material needs and to use recycled materials).

111e combinati7 of sustainable design strategies and BIM technology has the potential to change the traditional design practices and produce a high-performance facility design. One such effort in the Columbia campus of the University of South Carolina resulted in approximately $900,000 savings over the next ten years at current energy costs (Gleeson 2008).

BIM and sustainable design

BIM tools facilitate sustainable design. 111ey provide for:

• Structural design analysis, • Energy analysis, • Day lighting and lighting analysis, • Model viewing tools for design review, • Material database, • Database tools for construction management, • Database tools for facility management, and • Monitoring and controls.

BIM should therefore be viewed as one aspect of purpose-driven software. Construction stakeholders should understand this current limitation. As BIM is primarily a geometric model with parametric variables, it is capable of operating in tandem with many other purpose-driven software systems. Every effort should be made to ensure that interoperability is established in order to have the best possible results fro m the BIM technology. 111e IFC-based model exchange provides an ability to transfer objects, their relationshi~ and their associated property sets.

BIM and lean construction

BIM supports many initiatives that are critical to lean design and construction. As the fundamental principle of lean is to reduce or eliminate waste, BIM addresses many aspects of waste that occur first in the design phase, and later in the construction phase. Lean design p 19itiotes the active participation of construction stakeholders as early as the project definition phase. As the design concept is developed, designers, owners, and constructors can work interactively to make decisions that influence the overall project - in real time, concurrently. Traditional design reviews are treated as sequent}al events, long after significant design decisions have been made. At that point, changes can quickly become time-consuming and expensive. Furthermore, as many disciplines are involved in the design of a project, changes in some elements of the design may not be fully represented by all the disciplines. In traditional projects that oversighd ften m anifests itself as errors and omissions - classic examples of waste.

111e "Big RoOJ~" or obeya concept is adopted in lean construction fro m the Toyota Production System, and brings together cros~/unctional teams under one roof to explore problems. Team members generate synergy by collaboratington not just the design, but on the construction process required to bring it to fruition (Macomber and Howell 2005). BIM provides a critical platform for Big Room meetings. "\Vhat-if" games can be played with various design approaches and the results can be evaluated immediately. Target value design is enhanced with BIM. Cost impacts of design are quickly determined in a concurrent manner, instead of relying on the traditional estimating approach.

Clash detection is easily accomplished with BIM - design errors often include having different building systems C compete for the same limited space in ceilings and building penetrations from floor to floor. Air conditioning ducts -' and plumbing/fire protection piping typically compete for that space. \Vhen these clashes are detected during field fl' installation, corrective action can have significant consequences. Bends in ducts and pipes that were not part of.! he original design increase their equivalent length, and may restrict the flow of air or water below the desigJl levels defined by the mechanical engineer(s). 111at in turn leads to suboptimal building performance. i..I