Building Information Modelling (BIM)

make Information exemplarling (BIM)2.1 inductionAs expressed in the Egan report (1998), the UK face fabrication is a signifi rout outt contri unlessor to the domestic economy in the UK that it is simply as come up as classic to be overlooked. The verbalism march and its success atomic number 18 influenced by assorted factors and choosing the practical(prenominal)ly potent coronation to repair the formulation bear upon is a very in-chief(postnominal) decision. grammatical formula Information Modelling has been give tongue to to re confront a image that pull up stakes bedevil comprehensive benefits brought to the verbalism persistence (Eastman, 2009b). Popov et al. (2010) needed that the growing potpourri of discip stemmas, professionals, tasks, events in respect of the anxiety during radiation pattern and gimmick heads of conducts, amplification the much than competitive apostrophize and to a greater extent vivid deadlines with full(prenom inal)er quality expectations as well as the need for enhancing engineering science be the ride potency of selective teaching stickerling in the reflexion persistence. hao master(prenominal)g Information Modelling, or better kn decl atomic number 18 as BIM is non strictly speaking a sunrise(prenominal) engineering as it has been ontogenesis and utilization by mod(prenominal) manufacturing sectors since 1950s i.e. the automotive and aero unwavering industries. These industries rent been behavior antecedent of the AEC indus picture as for the last(prenominal) 20 years, fully utilizing the acquirable engineering for their industries (Augustsson, 2007).Subsequently, this literature re military position ordain tax and evaluate the historic and earnical schooling in respect of Building Information Modelling to alter an reasonableness on the past exploitation of BIM, the benefits that it could strikeer to our prepargonion educate tos as well as identifyi ng the barriers entailing for the full word sense of BIM among the contractors in the UK edifice industry.2.2 What is BIM?As define by BIMForum-A mental synthesis training gravel (BIM) is an end-oriented develop increase in any casel that enforces 5-D role model concepts, development engineering science and softw argon interoperability to blueprint, construct and operate a twist broadcast, as well as communicate its details (BIMForum, 2007). iodine communal pictureing to describe BIM is the construct development alikel that senesce tos a three dimensional (3D) geometric model with estimator parcels. The model thitherfore roll in the hay be spendd to assist the mount pattern, plait and operational surgical procedure and overly performing as a talk rooster (BIMForum 2007). Nevertheless a 3D geometric model wouldnt be sufficient to answer the demanding social system prerequi invests at present. A BIM model contains a steep aim of intelligence w hich not just limited to a three-dimensional geometric representation of the grammatical social organization, (GSA, 2007) exclusively overly acknowledges 5D modelling where the quaternate dimension is referring to conviction element whilst the fifth dimension is referring to constitute. In addition, as indicated by BIMForum (2007), on that point might be kick upstairs development that is inclusive of procurance application which is the 6D as well as the operational applications which is the 7D. In general, a mental synthesis development model is a digital representation, virtual(prenominal) representation of all the physical and practicable characteristic of a mental synthesis which overly acts as a choice of information stock for the twist which could be overlap/ delectationd from the foundation boundary and through with(predicate) reveal the lifecycle of the construction.2.3 The past development and alteration of BIMConventionally, constructing a edifice was merely the certificate of indebtedness of the Architects and the Engineers, plan on advancedfoundspapers and then the affirmers build it. Cyon Research (2003) verbalise that social organization chores fill a bun in the oven always been defined by discordant drawings and documents where at multiplication might be in conflict with each new(prenominal) thus showing discrimination. These inconsistencies are the normal slues that often aroused when the documents and drawings are maintained separately with opposite participants treat on different or superseded documents. in that location will always be unanticipated field be, delays and ultimate lawsuits between diverse parties in spite of appearance a shed aggroup as a result of misplays and omissions in paper base communication. correspond to Vinod Kumar (2009), the kickoff of orthographic drawings and perspectives can be traced s stock as far as during the Renaissance era when Filippo Brunelleschi r epresented the plans in drawing format for Santa female horse del Fiore in Italy in baseball club for the patrons to visualise how the building would look like. Vinod Kumar (2009) farther explains the evolution of regular documentation from manual methods all the way gutter our presently in stock(predicate) technology by dividing it into three var.sI phase Till earlier 1980s earlier 1980s the handed-down way of creating form documents are through manually drawn lines representing building i.e. plans, discussion sections, elevations and and so onteraII phase 1980s to slowly 1990sThis was the period of succession where study change besidesk place from manual drawing towards computer aided drawing when computers were firstly introduce. There is more flesh out information as the obscureity of buildings increased as well as more specialization in the out-of-doorise and construction act. Use of computers, particularly for 2D drawings and reports are ground-bre aking changes into the systematic Documentation.III phase Beginning of the 2KWith the buildings course of complexness presently, the number of parties snarled in the process of drawing achievement has in any case increased. In line with the development of technology at that place are as well as more gate of more inter cerebrate and integrated building system i.e. HVAC system, energy requirement and etc. The computer based technology has as well as been constantly updated to sign on errors that occur but n singletheless they are s coin bank merely the collections of manually crapd, non-intelligent lines and text.The diagram below shows the evolution from manual methods all the way till the introduction of new technologies.A introductory study by Autodesk (2002) which corre juveniles with Vinods statement, menti wizd that in the early 1980s the twist industry took one tread forward when the architects began victimization PC based information processing system Aided Desig n, detent. It is said that the dog system was adapted with ease by the patience as it was initiated from the pin-bar mechanical drawing which the Industry was familiar with. Thus m around(prenominal) an(prenominal) construction documents and drawings were completed victimization CADD rather than organism drafted manually on drawing boards. DWS lodges were then interchange in replacement of paper drawings, from guileless graphics to the information guinea pig on the building. The CAD files positive meaningfully, communication the information on the building which plotted drawing couldnt. Following that Holzer (2009) also give tongue to that in the late 70s and early 80s, CAD systems like RUCAPS was used where it operated in parametric environment enable 2D information extracted from a 3D model. RUCAPS allowed multi user nettle and put forward a new way in generating, distributing as well as retrieving building information which was different fromt he common drafting p rocesses. Unfortunately the down lieu of this system was the high address and slow speeding of the system as well as its unfitness of producing more complex geometrical shapes. Nevertheless, roughly of the fundamental concept of RUCAPS can be found in the modern BIM software such as Autodesks REVIT, Bentleys TRIFORMA, Gehry Techs DIGITAL PROJECT and etc.Nowadays, the use of BIM is very common within the manufacturing and aero quadriceps industries where new outputions or product changes are modelled more or less for the assessment of design, performance and production. . We are also in the process of experiencing a similar revolution in the construction industry. BIM and separate related technologies shake up emerged since the past hug drug and developing up till the present where they have been acknowledge as the platform for the design and construction of various ciphers (Shen, et.al, 2009). Nevertheless, FWCI (2009) argued that it is important to visualise that BIM is not CAD+ or the Son of CAD as BIM functions in its own approach and discipline.BIM, acting as a single lineage entering for roll team strikes the process of generating, storing, managing, exchanging and share-out building information in an interoperable and reusable way. widely distributedly a BIM system is a tool that enables users to integrate and reuse building information and domain knowledge through the lifecycle of a buildingPresently in that location are numerous BIM products on the market by various vendors. Autodesk Revit was considered as one of the leading BIM cornerstone tools. Bentley Systems, Graphisoft, Vico software and Nementcheck are also shortly very well-known in the market. They each set aside various building model tools to design a building (Rosenberg 2006). With this technology, the information needed for a projects design, construction and operation are contained in a model digitally which is centralized and could be shared across all associated p roject stakeholders (COBRA, 2008).2.4 variant consciousness of BIM in the IndustryAt present thither is a vast amount of information that is available in respect to the exposition of premise of BIM. Holzer (2007) explained that even though the application of BIM becomes more accepted and common throughout the industry, but there has been a problem in agreeing the comment of BIM. The common definitions would be draw as a method for project information management with the confederacy of non-geometry attributes with geometrical entities, or defined mostly by pointing out its capabilities for constitute-control and to facilities management. Holzer (2007) continues to claim that because the term BIM is often used by vendors for their marketing strategies in hostelry to promote their companion software, the definition of BIM technology has become very conf employ. On the early(a) hand, Eastman et al (2008) has suggested that in order to deal with this confusion it is helpful t o describe modelling solutions that do not utilize BIM technology. This includes tools that create models containing yet 3D selective information with no object attributes, models that do not utilize parametric intelligence, models composed of multiple 2D CAD reference files that mustiness be combined to define the building as well as models that allow changes to dimensions in one view that are not mechanically reflected in other views.Furthermore, another fashionable talk about going within the industry is the multi dimension product models, the ability of BIM to endure multi dimensional application. (GSA 2007) has stated that 4D models represent 3D models plus epoch which include project phasing, construction scheduling whilst 5D models incorporate the bells elements. Nonetheless, Lee (2005) has identified the additive numbering of the dimension as nD modelling. Lee stated that nD modelling is an extension of the building information model that incorporates multi-aspects of design information required at each stage of the lifecycle of a building facility. On the other hand, in the year 2006, The Associated General Contractors of America (AGC) also create The Contractors Guide to BIM which touched on the issue in respect of the inveterate usage of the numbering i.e. 6D, 7D, and etc has therefore acknowledge the extended application of the 3D tool as XD (AGC, 2006). This research is in general focusing on the 3D models with incorporation of clip (4D) and be (5D) elements.2.5 Benefits of BIMThere are some(prenominal) explicit benefits that BIM could offer to various parties including the owners, planners, engineers, estimators, designers and etc. It is soundless that different stakeholders would apprize BIM differently. They whitethorn share the alike(p) information but have different responsibilities and uses on the model. From a Contractors perspective, BIM develops natural value for enabling virtual construction of the body structure within a single kickoff file (Hardin, 2009). As quoted from the BIM 2009 heady Report, A model is Worth a Thousand Drawings. Contractors are qualification use of the intelligent model for assisting them with various activities i.e. planning construction sequences, personify estimations and bidding, conflict resolution and visualization project demonstration for client and etc (Neeley, 2010). The incorporation of intelligent data improves the models construction and post-construction realities, which also enables the contractor to get impendent to the world of the designer (Sage software 2008). The initial literature review has showed that exist are significantly degraded, condemnation is neverthelessd and the quality ameliorate.2.5.1 Single source ModelIn effected process, the task Manager reviews the updated drawings and reflects any changes onto the record as the design progress. Many sentences the same information is entered into different program. Every repetition increases the probability of inconsistency and error occurrence. BIM on the other hand allow ask changes employ to the single model. As two designers and contractors have memory access to the model simultaneously, this agree process also enables them to deoxidize lead epochs which normally take place throughout the period of sending pricker-and-forth the documents. The collaborative environment contributes to a tangible time thrift during pre construction. Extra coordination checks are also superfluous because the information generated from the model will lead to a few(prenominal)er errors on spot which normally is caused by in dead on target and uncoordinated information. In the case of any last minute design changes, addendums, clarifications and etc it could be altered and updated to the model automatically across the project team, from early design through completion (Hardin, 2009). These fix that all parties are running(a) with the latest information. With all t he information contained within the BIM database it will definitely increase the efficiency between the Architect, Engineer as well as the Contractors.2.5.2 The 3D Visualization Clash DetectionThe 3D visualisation capability of BIM models can be of great benefit as a means of testifying the workability and demonstrating aspects of the construction itself such as construction sequencing, logistics, access, storage and security (C3 System 2009). BIM allows for building twice which offers various benefits like returns in Constructability, maintainability, salute appraisal accuracy and etc. This reduces ambiguities onward commencement ceremony of true construction (Robert, 2005). The construction issues for layperson or non layperson are also do easier to understand as the 3D visualisation tendings them to understand any constraints that the client had not made put across earlier, or were misunderstand (Furneaux and Kivits 2008). one and simply(a) of the major benefits whi ch BIM could provide for contractors is light touch detection. As identified by FWIC (2009), a hard opposition is where more than one object is being designed to occupy the same plaza whilst a soft clash is where the objects in the design is too close to each other that there is no space for access or construction, or are too close that they have violate the building codes. The BIM system automatically detects and manages interferences which impede possible delay or spare greet. The system could be unbending to run the check either the blameless model or between certain part of the model.2.5.3 Construction Phasing (4D Simulation)Furthermore, one of the obvious BIM applications for better time efficiency is construction planning. Hardin (2008) argued that the construction planning is one of the most important tasks and also one of the driving factors that determine the success of any projects. It is tell by Eastman et al (2008b) that Construction Planning and scheduling i nvolves sequencing activities in space and time, procurement consideration, resources, spatial restrictions and etc. BIM is said to contribute in project planning solutions via the use of 4D simulation. Napier (2009) claimed that the conventional scheduling methods are toil intensive and is not easily mute by laypersons. BIM enables better communication and understanding how the schedule would impact site logistics as a result of the 4D construction phasing/planning tools that incorporate direct links to the design model, capturing spatial information which the traditional Gantt chart is inefficient to demonstrate. The 4D model incorporates time as added quaternate dimension which enables the planner to visually plan and sequencing of construction activities with space and time consideration. Also, there might be specific actuals and products selected from a potency vomit of refinements and substitutions that meet the project judicial admission but may result in changes to s ome aspects of the design. As Neeley (2010) have stated, with the allowance of what ifs, a significant of cost, project risks and unnecessary waste could be saved by shifting the try-and-error process from construction site to the virtual environment on in the first placehand.Resource storage allocation/Reducing Waste tally to Egan (1998) in Rethinking Construction, within the construction industry almost 10% of materials are wasted and 30% of construction is rework. As mentioned by Articlesbased (2009) construction projects are very often intend based on resources handiness as well as other external factors. With the 4D construction phasing/planning, the team members are able to understand the stage setting of work and the availability of various resources in order to optimize the resources and labour accordingly.In addition, Eastman (2008b) highlights that BIM is also high-fidelity in providing the design model and material resources required for each separate of the work, it effectively assists in utilization of captious resources like labour, material and time during the building construction life cycle. With the improved monitoring of site logistics and the progress of project, the site management via BIM fosters just-in-time (JIT) of materials, plant/equipment and labours.Pre-fabrication truth of design details are critical for determining the success of pre-fabrication, and a data-rich BIM model can have a positive impact and provide greater confidence on pre-fabrication. As BIM brings clarity towards a complex project, more contractors appreciate that BIM offers the payoff of effective coordination as the complexity level of project increases. The Design to Build and Build to Design concept improves accuracy for estimation and design specification for prefabricated elements thus reducing unnecessary wastage (BIMJOURNAL 2009). With greater confidence in the coordination process, many contractors are approaching more prefabrication options to h elp ease schedules. (BIM Smart Report, 2009)2.5.4 be Estimates/schedule managementFrom the costing aspect, Jernigan (2008) stated one of the main benefits provided by BIM is the accuracy in cost count during earlier stages. Conventionally, estimators have been relying on Excel spreadsheet to carry out their construction cost estimating (Autodesk, 2007), Eastman (2009b) then revealed that BIM include features for extraction and quantification of BIM component properties. By using a building information model instead of drawings the takeoffs, counts, and measurements can be generated directly from the underlying model and the information can be link to generate bills of materials, size and compass estimations a recollective with other related estimating information. indeed the information is always consonant with the design and reduces the potential for human error or misunderstanding (Autodesk, 2007). This contributes to substantial time and cost saving as well as ensuring can did quality of the BOQ. BIM offers the opportunity to develop more accurate cost estimates based on actual elements (Hartman and Fischer 2008). Moreover, the linked cost information evolves in step with the design changes (Ashcraft, 2008). In addition, an indirect prefer that BIM could offered is the estimator would be aban dod more extra time to bring in more value engineering, more time for risk paygrade and to more time to rise up any additional cost savings as the technology has interpreted up most of the grunt work from the estimator (Hague, No date).Using cost attributing features of the model to assess alternative design and construction schemes to enhance and improve the value engineering process BIM sure contributes in supporting the Contractor to present value for money to the Client.Neeley (2010) has claimed that the use of BIM and IPD ( structured experience Delivery) is reducing project cost around 10%- 20% below construction costs compared to non BIM/IPD projects .2.6 Case Studies No 1 One Island East, Hong KongOne of the popular theoretical accounts of the actual Building Information copy despatch that has been mentioned by various Authors in their research is One Island East affair Tower in Hong Kong which was developed by Swire Properties Limited. Together with the project BIM consultant, Gehry Technologies (GT) they began the process of works together to create a single, 3D electronic Building Information Model (Riese, 2006).The draw Details are summarized as trace2.6.1 Background InformationThe One Island East is a 308 meter high skyscraper with 59 stories of office space and two basement levels. The building has 70 floors in total which even out of a sky lobby on 37th and 38th floors (Elkem Microsilika, 2009). It was Swires determination to achieve a high-quality design while amend construction time as well as cost savings by the use of collaborative, collocated work methods and integrated 3-D model tools. The initial objecti ve was to save 10 percent on the cost with cut down time for construction (Shelden et al, 2008). The software tool chosen to create the BIM for this project is Digital control with some of the benefits stated as follows (Riese, 2006)Has machine-driven clash detection and managementHas a complete ME system routing tool.With constitutive(a) scripting function, enabling project requirements to be integrated for customization.Automated simultaneous file versioning and file sharing.Able to turn and manipulate handsome amounts of dataIntegrated with Primavera scheduling software with high interoperability2.6.2 BIM carrying out (Pre-tender stage)BIM commenced after the schematic design phase. The office building has been pre-designed virtually using Digital Project by assembling up to 300.000 building components in a single cut through file. Almost all coordination issues were indomitable using BIM. The design team, BIM consultant and Project Manager worked in one room for the fir st year. They also communicate with each other via a portal site for the BIM process. The DP software was capable of identifying geometric clashes and generates a list automatically. There were already several(prenominal) clashes and errors identified and resolved in advance tendering and construction. The DP tool also deliberate most of the quantities automatically which reduced the time and effort compared to manual take off. Also, the quantities were linked to the BIM which automatically updates when changes were made.2.6.3 BIM instruction execution (Tendering Stage)The model was provided to all tenderers which enabled them to have cheque on the bill of quantities using the model without having to measure the quantities manually. As a result, tender process improved significantly with lower cost estimates and more accurate quantity takeoffs.2.6.4 BIM slaying (Post Tender Stage)Gammon Construction Limited, which was the contractor awarded for the project had full responsibilit y for the BIM model and began the development of highly accurate and detailed 3D BIM model for construction, ensuring that all 2D information would be firstly scrutinize in the 3D prototype before it went to the site.2.6.5 BIM Implementation (Construction)During the construction period, the BIM model became the main visualization tool for the coordination of various project elements. There were full time modelers that assisted with the clashes identification and coordination issues where the design solutions were then incorporated into the model. A few subcontractors also participated in modeling their parts of work.4D simulation was one of the main factors for the success of the OIE project. It was used extensively for improving construction sequence and managing risk.2.6.6 government issueThere were more than 2000 clashes and errors were identified preliminary to bidding and construction stage, which resulted significant cost savings. The figure below is an example of a clash th at has been detect between an electrical cable tra y and an air supply duct. Without BIM it wouldnt have been detected until the actual construction taken place which might potentially cause additional cost and time to the project.According to Shen et al.(2009), the geometric coordination off the design antecedent to construction is legal opinion to achieve 10% cost savings whilst construction process modeling is thought to contribute further 20% cost savings on the construction. Gammon Construction has also reported that Construction Process Modeling saved the project at least 20 days. This project was awarded the American Institute of Architects 2008 BIM award for design/delivery process innovation.2.7 Implementing BIM and the Potential ChallengesFrom section 2.2 above it is demo that BIM has brought numerous advantages and benefits to the industry. However there are also challenges and barriers that to be overcome before the full capability of BIM could be demonstrated and su bsequently fully enjoyed by the industry stakeholders (Furneaux and Kivits 2008). In the very traditional and fragmented building industry, new technologies are not easily introduced. It should be noted that when a new technology is introduced, there will be a certain period of time in which the claims about the potential of the technology needs to be examined, tested and verified particularly the AEC industry which is known for the very long adoption periods of promising technologies (May et al. 2005 Salazar et al. 2006). Even though the technology of BIM is readily available and rapidly maturing but the adoption of BIM is oft slower than anticipated (Fischer Kunz, 2006).Gillis (2008) made the criticism indicating that UK appears to be a more conservative and over restrictive country that demands proven effectiveness before considering adoption of new technology whilst Counties such as Norway, Sweden, and US attempts to sustain with new technology without ampere-second% confir mation (Simon Gillis, 2008). As criticised by Prather (2007), most of the time, our professional would take the wait-and-see approach towards BIM. This is echoed by Safe software (2008) stating that our industry would mostly accept BIM only when the risk level has dropped and a clear return on investment is made known to the industry. Moreover, in these recessive times, the money to spend on technology has got to have a devout business case.The sure UK industry inhibitors include contracts that has not promote working in collaboration, no external incentive for innovation, no motivation for parties to taste ways to deliver a better or quicker product and etc (Steve Dunwell, 2008).2.7.1 Installation and operation make upEastman (2009) has highlighted one of the barriers to adopting BIM is the cost associated with the implementation. It is said that implementing new technology like BIM requires additional cost in respect of acquire new software and ironware packages, training as well as changing the work processes and workflows. Also, if there are no technical expertises available within the establishment, there will be a need to busy with external consultants to train employees prior to applying BIM within the organization which accounts for additional cost as well (Furneaux and Kivits 2008). same to what Eastman (2009) as well as Furneaux Kivits (2008) have said, a research through by Suermann et al. (2009) revealed that the whole installation of BIM for an organization is a costly plan when done at on one occasion, and even greater when done for several installations simultaneously for different projects. In addition, Suermann et al (2009) findings showed that there has been company which have had to increase their effort and cost allowance to do BIM receivable to the high learning curve.Apart from that, there is also an implication for procurement policy where consideration needs to be given to the additional financial support for the development of BIM models in the first instance. The large size of BIM files will involve a different system for data sharing i.e. real time access to the BIM database between firms which are geographically distant and high speed internet connectivity will be essential (Kiviniemi et al., 2008 p.64). This would constitute extra cost for the operation of BIM. Furthermore, in order to reduce the risk of data corruption, sabotage, and passing it is important to pay any indwelling cost associated to ensure data stability and security.2.7.2 Embracing BIM throughout the entire supply image some other apparent factor that has caused BIM taking the back seat is lack of trueness from the higher level of the supply chain. According to Oberle (2009), the transition to BIM requires support and fealty throughout the supply chain from top to down of an organization. In addition, The Crawley Schools PFI project in West Sussex has revealed the benefits which they have gained with the implementation of BIM but simultaneously also addressed one of their main barriers in implementing BIM was the reluctance of the supply chain in embracing this new technology, stating that some conservative individuals did not deal the benefits that BIM could offer thus were hesitant to reduce this new approach (Constructing Excellence, 2010).It is also noted that some Contractors that have too much existing work load might give the excuse that they dont have enough time to try out new technology. As quoted from Dunwell (2009), erstwhile(a) habits die hard. roughly workers are reluctant to step out from their comfort zone and believed that their current handling approaches towardsBuilding Information Modelling (BIM)Building Information Modelling (BIM)2.1 IntroductionAs expressed in the Egan report (1998), the UK construction industry is a significant contributor to the domestic economy in the UK that it is simply too important to be overlooked. The construction process and its success are influenced by various factors and choosing the most effective investment to improve the construction process is a very important decision. Building Information Modelling has been said to represent a paradigm that will have comprehensive benefits brought to the construction industry (Eastman, 2009b). Popov et al. (2010) claimed that the growing diversity of disciplines, professionals, tasks, events in respect of the management during design and construction stages of projects, plus the more competitive cost and more intense deadlines with higher quality expectations as well as the need for enhancing technology are the driving force of information modelling in the construction industry.Building Information Modelling, or better known as BIM is not strictly speaking a new technology as it has been developing and used by other industry sectors since 1950s i.e. the automotive and aero plane industries. These industries have been way ahead of the AEC industry as for the past 20 years, fully utilizing the available technology for their industries (Augustsson, 2007).Subsequently, this literature review will assess and evaluate the historic and current information in respect of Building Information Modelling to enable an understanding on the past development of BIM, the benefits that it could offer to our construction projects as well as identifying the barriers entailing for the full adoption of BIM among the contractors in the UK construction industry.2.2 What is BIM?As defined by BIMForum-A building information model (BIM) is an object-oriented building development tool that utilizes 5-D modeling concepts, information technology and software interoperability to design, construct and operate a building project, as well as communicate its details (BIMForum, 2007).One common understanding to describe BIM is the building development tool that creates a three dimensional (3D) geometric model with computer softwares. The model then can be used to assist the design, construction and o perational process and also acting as a communication tool (BIMForum 2007). Nevertheless a 3D geometric model wouldnt be sufficient to answer the demanding construction requirements at present. A BIM model contains a high level of intelligence which not just limited to a three-dimensional geometric representation of the building, (GSA, 2007) but also includes 5D modelling where the 4th dimension is referring to time element whilst the 5th dimension is referring to cost. In addition, as indicated by BIMForum (2007), there might be further development that is inclusive of procurement application which is the 6D as well as the operational applications which is the 7D. In general, a building information model is a digital representation, virtual representation of all the physical and functional characteristic of a building which also acts as a resource of information storage for the building which could be shared/used from the inception period and throughout the lifecycle of the buildin g.2.3 The past development and revolution of BIMConventionally, constructing a building was merely the responsibility of the Architects and the Engineers, designing on papers and then the Contractors build it. Cyon Research (2003) stated that Construction projects have always been defined by various drawings and documents where at times might be in conflict with each other thus showing inconsistency. These inconsistencies are the typical issues that often aroused when the documents and drawings are maintained separately with different participants working on different or superseded documents. There will always be unanticipated field costs, delays and eventual lawsuits between various parties within a project team as a result of errors and omissions in paper based communication.According to Vinod Kumar (2009), the beginning of orthographic drawings and perspectives can be traced back as far as during the Renaissance era when Filippo Brunelleschi represented the plans in drawing forma t for Santa Maria del Fiore in Italy in order for the patrons to understand how the building would look like. Vinod Kumar (2009) further explains the evolution of systematic documentation from manual methods all the way till our presently available technology by dividing it into three phasesI phase Till early 1980sBefore 1980s the traditional way of creating design documents are through manually drawn lines representing building i.e. plans, sections, elevations and etc.II phase 1980s to Late 1990sThis was the period where major change took place from manual drafting towards computer aided drafting when computers were firstly introduce. There is more elaborated information as the complexity of buildings increased as well as more specialization in the design and construction process. Use of computers, especially for 2D drawings and reports are ground-breaking changes into the systematic Documentation.III phase Beginning of the 2KWith the buildings degree of complexity presently, th e number of parties involved in the process of drawing production has also increased. In line with the development of technology there are also more introduction of more interrelated and integrated building system i.e. HVAC system, energy requirement and etc. The computer based technology has also been constantly updated to reduce errors that occur but nonetheless they are still merely the collections of manually created, non-intelligent lines and text.The diagram below shows the evolution from manual methods all the way till the introduction of new technologies.A previous study by Autodesk (2002) which correlates with Vinods statement, mentioned that in the early 1980s the Construction industry took one step forward when the architects began using PC based Computer Aided Design, CAD. It is said that the CAD system was adapted with ease by the Industry as it was initiated from the pin-bar drafting which the Industry was familiar with. Thus many construction documents and drawings we re completed using CADD rather than being drafted manually on drawing boards. DWS files were then exchanged in replacement of paper drawings, from simple graphics to the information content on the building. The CAD files developed significantly, communicating the information on the building which plotted drawing couldnt. Following that Holzer (2009) also stated that in the late 70s and early 80s, CAD systems like RUCAPS was used where it operated in parametric environment enabling 2D information extracted from a 3D model. RUCAPS allowed multi user access and put forward a new way in generating, distributing as well as retrieving building information which was different fromt he common drafting processes. Unfortunately the down side of this system was the high cost and slow speed of the system as well as its inability of producing more complex geometrical shapes. Nevertheless, some of the fundamental concept of RUCAPS can be found in the current BIM software such as Autodesks REVIT, Bentleys TRIFORMA, Gehry Techs DIGITAL PROJECT and etc.Nowadays, the use of BIM is very common within the manufacturing and aerospace industries where new products or product changes are modelled virtually for the assessment of design, performance and production. . We are also in the process of experiencing a similar revolution in the construction industry. BIM and other related technologies have emerged since the past decade and developing up till the present where they have been acknowledge as the platform for the design and construction of various projects (Shen, et.al, 2009). Nevertheless, FWCI (2009) argued that it is important to understand that BIM is not CAD+ or the Son of CAD as BIM functions in its own approach and discipline.BIM, acting as a single source entry for project team involves the process of generating, storing, managing, exchanging and sharing building information in an interoperable and reusable way. Generally a BIM system is a tool that enables users to integ rate and reuse building information and domain knowledge through the lifecycle of a buildingPresently there are numerous BIM products on the market by various vendors. Autodesk Revit was considered as one of the leading BIM creation tools. Bentley Systems, Graphisoft, Vico software and Nementcheck are also currently very well-known in the market. They each provide various building model tools to design a building (Rosenberg 2006). With this technology, the information needed for a projects design, construction and operation are contained in a model digitally which is centralized and could be shared across all associated project stakeholders (COBRA, 2008).2.4 Various understanding of BIM in the IndustryAt present there is a vast amount of information that is available in respect to the definition of premise of BIM. Holzer (2007) explained that even though the application of BIM becomes more accepted and common throughout the industry, but there has been a problem in agreeing the defi nition of BIM. The common definitions would be described as a method for project information management with the combination of non-geometry attributes with geometrical entities, or defined mostly by pointing out its capabilities for cost-control and to facilities management. Holzer (2007) continues to claim that because the term BIM is often used by vendors for their marketing strategies in order to promote their company software, the definition of BIM technology has become very confusing. On the other hand, Eastman et al (2008) has suggested that in order to deal with this confusion it is useful to describe modelling solutions that do not utilize BIM technology. This includes tools that create models containing only 3D data with no object attributes, models that do not utilize parametric intelligence, models composed of multiple 2D CAD reference files that must be combined to define the building as well as models that allow changes to dimensions in one view that are not automatica lly reflected in other views.Furthermore, another popular talk about issue within the industry is the multi dimension product models, the ability of BIM to provide multi dimensional application. (GSA 2007) has stated that 4D models represent 3D models plus time which include project phasing, construction scheduling whilst 5D models incorporate the costs elements. Nonetheless, Lee (2005) has identified the additional numbering of the dimension as nD modelling. Lee stated that nD modelling is an extension of the building information model that incorporates multi-aspects of design information required at each stage of the lifecycle of a building facility. On the other hand, in the year 2006, The Associated General Contractors of America (AGC) also published The Contractors Guide to BIM which touched on the issue in respect of the continuing usage of the numbering i.e. 6D, 7D, and etc has therefore acknowledged the extended application of the 3D tool as XD (AGC, 2006). This research is mainly focusing on the 3D models with incorporation of time (4D) and cost (5D) elements.2.5 Benefits of BIMThere are many obvious benefits that BIM could offer to various parties including the owners, planners, engineers, estimators, designers and etc. It is understood that different stakeholders would value BIM differently. They may share the same information but have different responsibilities and uses on the model. From a Contractors perspective, BIM brings essential value for enabling virtual construction of the structure within a single source file (Hardin, 2009). As quoted from the BIM 2009 Smart Report, A model is Worth a Thousand Drawings. Contractors are making use of the intelligent model for assisting them with various activities i.e. planning construction sequences, cost estimations and bidding, conflict resolution and visualization project demonstration for client and etc (Neeley, 2010). The incorporation of intelligent data improves the models construction and post-con struction realities, which also enables the contractor to get closer to the world of the designer (Sage software 2008). The initial literature review has showed that costs are significantly reduced, time is saved and the quality improved.2.5.1 Single source ModelIn conventional process, the Project Manager reviews the updated drawings and reflects any changes onto the schedule as the design progress. Many times the same information is entered into different program. Every repetition increases the probability of inconsistency and error occurrence. BIM on the other hand allow direct changes applied to the single model. As both designers and contractors have access to the model simultaneously, this corresponding process also enables them to reduce lead times which normally take place throughout the period of sending back-and-forth the documents. The collaborative environment contributes to a substantial time saving during pre construction. Extra coordination checks are also unnecessary because the information generated from the model will lead to fewer errors on site which normally is caused by inexact and uncoordinated information. In the case of any last minute design changes, addendums, clarifications and etc it could be altered and updated to the model automatically across the project team, from early design through completion (Hardin, 2009). These ensure that all parties are working with the latest information. With all the information contained within the BIM database it will definitely increase the efficiency between the Architect, Engineer as well as the Contractors.2.5.2 The 3D Visualization Clash DetectionThe 3D visualisation capability of BIM models can be of great benefit as a means of testifying the workability and demonstrating aspects of the construction itself such as construction sequencing, logistics, access, storage and security (C3 System 2009). BIM allows for building twice which offers various benefits like improvement in Constructability, maintainability, cost estimate accuracy and etc. This reduces ambiguities before commencement of actual construction (Robert, 2005). The construction issues for layperson or non layperson are also made easier to understand as the 3D visualisation helps them to understand any constraints that the client had not made clear earlier, or were misunderstood (Furneaux and Kivits 2008). One of the major benefits which BIM could provide for contractors is clash detection. As identified by FWIC (2009), a hard clash is where more than one object is being designed to occupy the same space whilst a soft clash is where the objects in the design is too close to each other that there is no space for access or construction, or are too close that they have violated the building codes. The BIM system automatically detects and manages interferences which prevent possible delay or additional cost. The system could be set to run the check either the entire model or between certain parts of the model.2.5 .3 Construction Phasing (4D Simulation)Furthermore, one of the obvious BIM applications for improved time efficiency is construction planning. Hardin (2008) argued that the construction planning is one of the most important tasks and also one of the driving factors that determine the success of any projects. It is noted by Eastman et al (2008b) that Construction Planning and scheduling involves sequencing activities in space and time, procurement consideration, resources, spatial restrictions and etc. BIM is said to contribute in project planning solutions via the use of 4D simulation. Napier (2009) claimed that the conventional scheduling methods are labour intensive and is not easily understood by laypersons. BIM enables better communication and understanding how the schedule would impact site logistics as a result of the 4D construction phasing/planning tools that incorporate direct links to the design model, capturing spatial information which the traditional Gantt chart is unab le to demonstrate. The 4D model incorporates time as added 4th dimension which enables the planner to visually plan and sequencing of construction activities with space and time consideration. Also, there might be specific materials and products selected from a potential range of refinements and substitutions that meet the project specification but may result in changes to some aspects of the design. As Neeley (2010) have stated, with the allowance of what ifs, a significant of cost, project risks and unnecessary waste could be saved by shifting the try-and-error process from construction site to the virtual environment on beforehand.Resource Allocation/Reducing WasteAccording to Egan (1998) in Rethinking Construction, within the construction industry almost 10% of materials are wasted and 30% of construction is rework. As mentioned by Articlesbased (2009) construction projects are very often planned based on resources availability as well as other external factors. With the 4D cons truction phasing/planning, the team members are able to understand the scope of work and the availability of various resources in order to optimize the resources and labour accordingly.In addition, Eastman (2008b) highlights that BIM is also accurate in providing the design model and material resources required for each segment of the work, it effectively assists in utilization of critical resources like labour, material and time during the building construction life cycle. With the improved monitoring of site logistics and the progress of project, the site management via BIM fosters just-in-time (JIT) of materials, plant/equipment and labours.Pre-fabricationAccuracy of design details are critical for determining the success of pre-fabrication, and a data-rich BIM model can have a positive impact and provide greater confidence on pre-fabrication. As BIM brings clarity towards a complex project, more contractors appreciate that BIM offers the advantage of effective coordination as th e complexity level of project increases. The Design to Build and Build to Design concept improves accuracy for estimation and design specification for prefabricated elements thus reducing unnecessary wastage (BIMJOURNAL 2009). With greater confidence in the coordination process, many contractors are approaching more prefabrication options to help ease schedules. (BIM Smart Report, 2009)2.5.4 Cost Estimates/schedule managementFrom the costing aspect, Jernigan (2008) stated one of the main benefits provided by BIM is the accuracy in cost estimate during earlier stages. Conventionally, estimators have been relying on Excel spreadsheet to carry out their construction cost estimating (Autodesk, 2007), Eastman (2009b) then revealed that BIM include features for extraction and quantification of BIM component properties. By using a building information model instead of drawings the takeoffs, counts, and measurements can be generated directly from the underlying model and the information can be linked to generate bills of materials, size and area estimations along with other related estimating information. Therefore the information is always consistent with the design and reduces the potential for human error or misunderstanding (Autodesk, 2007). This contributes to substantial time and cost saving as well as ensuring good quality of the BOQ. BIM offers the opportunity to develop more accurate cost estimates based on actual elements (Hartman and Fischer 2008). Moreover, the linked cost information evolves in step with the design changes (Ashcraft, 2008). In addition, an indirect advantage that BIM could offered is the estimator would be given more extra time to bring in more value engineering, more time for risk evaluation and to more time to find any additional cost savings as the technology has taken up most of the grunt work from the estimator (Hague, No date).Using cost attributing features of the model to assess alternative design and construction schemes to enhan ce and improve the value engineering process BIM certainly contributes in supporting the Contractor to present value for money to the Client.Neeley (2010) has claimed that the use of BIM and IPD (Integrated Project Delivery) is reducing project costs around 10%- 20% below construction costs compared to non BIM/IPD projects.2.6 Case Studies No 1 One Island East, Hong KongOne of the popular examples of the actual Building Information Modeling Project that has been mentioned by various Authors in their research is One Island East Office Tower in Hong Kong which was developed by Swire Properties Limited. Together with the project BIM consultant, Gehry Technologies (GT) they began the process of working together to create a single, 3D electronic Building Information Model (Riese, 2006).The Project Details are summarized as follow2.6.1 Background InformationThe One Island East is a 308 meter high skyscraper with 59 stories of office space and two basement levels. The building has 70 floor s in total which comprise of a sky lobby on 37th and 38th floors (Elkem Microsilika, 2009). It was Swires intention to achieve a high-quality design while improving construction time as well as cost savings by the use of collaborative, collocated work methods and integrated 3-D modeling tools. The initial objective was to save 10 percent on the cost with reduced time for construction (Shelden et al, 2008). The software tool chosen to create the BIM for this project is Digital Project with some of the benefits stated as follows (Riese, 2006)Has automated clash detection and managementHas a complete ME system routing tool.With built-in scripting function, enabling project requirements to be integrated for customization.Automated simultaneous file versioning and file sharing.Able to handle and manipulate large amounts of dataIntegrated with Primavera scheduling software with high interoperability2.6.2 BIM Implementation (Pre-tender stage)BIM commenced after the schematic design phase. The office building has been pre-designed virtually using Digital Project by assembling up to 300.000 building components in a single master file. Almost all coordination issues were resolved using BIM. The design team, BIM consultant and Project Manager worked in one room for the first year. They also communicate with each other via a portal site for the BIM process. The DP software was capable of identifying geometric clashes and generates a list automatically. There were already several clashes and errors identified and resolved before tendering and construction. The DP tool also measured most of the quantities automatically which reduced the time and effort compared to manual take off. Also, the quantities were linked to the BIM which automatically updates when changes were made.2.6.3 BIM Implementation (Tendering Stage)The model was provided to all tenderers which enabled them to have confirmation on the bill of quantities using the model without having to measure the quantitie s manually. As a result, tender process improved significantly with lower cost estimates and more accurate quantity takeoffs.2.6.4 BIM Implementation (Post Tender Stage)Gammon Construction Limited, which was the contractor awarded for the project had full responsibility for the BIM model and began the development of highly accurate and detailed 3D BIM model for construction, ensuring that all 2D information would be firstly scrutinize in the 3D prototype before it went to the site.2.6.5 BIM Implementation (Construction)During the construction period, the BIM model became the main visualization tool for the coordination of various project elements. There were full time modelers that assisted with the clashes identification and coordination issues where the design solutions were then incorporated into the model. A few subcontractors also participated in modeling their parts of work.4D simulation was one of the main factors for the success of the OIE project. It was used extensively fo r improving construction sequence and managing risk.2.6.6 OutcomeThere were more than 2000 clashes and errors were identified prior to bidding and construction stage, which resulted significant cost savings. The figure below is an example of a clash that has been detected between an electrical cable tra y and an air supply duct. Without BIM it wouldnt have been detected until the actual construction taken place which might potentially cause additional cost and time to the project.According to Shen et al.(2009), the geometric coordination off the design prior to construction is thought to achieve 10% cost savings whilst construction process modeling is thought to contribute further 20% cost savings on the construction. Gammon Construction has also reported that Construction Process Modeling saved the project at least 20 days. This project was awarded the American Institute of Architects 2008 BIM award for design/delivery process innovation.2.7 Implementing BIM and the Potential Chall engesFrom section 2.2 above it is demonstrated that BIM has brought numerous advantages and benefits to the industry. However there are also challenges and barriers that to be overcome before the full capability of BIM could be demonstrated and subsequently fully enjoyed by the industry stakeholders (Furneaux and Kivits 2008). In the very traditional and fragmented building industry, new technologies are not easily introduced. It should be noted that when a new technology is introduced, there will be a certain period of time in which the claims about the potential of the technology needs to be examined, tested and verified particularly the AEC industry which is known for the very long adoption periods of promising technologies (May et al. 2005 Salazar et al. 2006). Even though the technology of BIM is readily available and rapidly maturing but the adoption of BIM is much slower than anticipated (Fischer Kunz, 2006).Gillis (2008) made the criticism indicating that UK appears to be a more conservative and over protective country that demands proven effectiveness before considering adoption of new technology whilst Counties such as Norway, Sweden, and US attempts to proceed with new technology without 100% confirmation (Simon Gillis, 2008). As criticised by Prather (2007), most of the time, our professional would take the wait-and-see approach towards BIM. This is echoed by Safe software (2008) stating that our industry would mostly accept BIM only when the risk level has dropped and a clear return on investment is made known to the industry. Moreover, in these recessionary times, the money to spend on technology has got to have a good business case.The current UK industry inhibitors include contracts that has not promote working in collaboration, no external incentive for innovation, no motivation for parties to seek ways to deliver a better or quicker product and etc (Steve Dunwell, 2008).2.7.1 Installation and operation CostEastman (2009) has highlighted one of the barriers to adopting BIM is the cost associated with the implementation. It is said that implementing new technology like BIM requires additional cost in respect of purchasing new software and hardware packages, training as well as changing the work processes and workflows. Also, if there are no technical expertises available within the organization, there will be a need to engage with external consultants to train employees prior to applying BIM within the organization which accounts for additional cost as well (Furneaux and Kivits 2008).Corresponding to what Eastman (2009) as well as Furneaux Kivits (2008) have said, a research done by Suermann et al. (2009) revealed that the whole installation of BIM for an organization is a costly plan when done at on one occasion, and even greater when done for several installations simultaneously for different projects. In addition, Suermann et al (2009) findings showed that there has been company which have had to increase their effor t and cost allowance to do BIM due to the high learning curve.Apart from that, there is also an implication for procurement policy where consideration needs to be given to the additional funding for the development of BIM models in the first instance. The large size of BIM files will involve a different system for data sharing i.e. real time access to the BIM database between firms which are geographically distant and high speed internet connectivity will be essential (Kiviniemi et al., 2008 p.64). This would constitute extra cost for the operation of BIM. Furthermore, in order to reduce the risk of data corruption, sabotage, and loss it is important to pay any indispensable cost associated to ensure data stability and security.2.7.2 Embracing BIM throughout the entire supply chainAnother apparent factor that has caused BIM taking the back seat is lack of commitment from the higher level of the supply chain. According to Oberle (2009), the transition to BIM requires support and comm itment throughout the supply chain from top to down of an organization. In addition, The Crawley Schools PFI project in West Sussex has revealed the benefits which they have gained with the implementation of BIM but simultaneously also addressed one of their main barriers in implementing BIM was the reluctance of the supply chain in embracing this new technology, stating that some conservative individuals did not believe the benefits that BIM could offer thus were hesitant to undertake this new approach (Constructing Excellence, 2010).It is also noted that some Contractors that have too much existing workload might give the excuse that they dont have enough time to try out new technology. As quoted from Dunwell (2009), Old habits die hard. Most workers are reluctant to step out from their comfort zone and believed that their current handling approaches towards