At the core of the development of many CAD tools for the AEC industry is the understanding that traditional barriers to communication must be brought down. One of the problems with traditional, paper-based methods is that they hinder effective and fluid communication between the architect, the client, on-site labour and other project partners. In the case of large, highly fragmented projects, with multiple project stakeholders, investors and subcontractors, the challenge of achieving fluid communication is compounded, but it exists on projects of all sizes. The construction process is often unique due to its fragmented organisation and the bespoke nature of the majority of construction projects. This leads to lack of feedback on completion of a building, and “little is known about how it is used or if the assumptions made in its design are born out in practice” (Laptali & Bouchlaghem 1995). Because the industry in general, and even the building site, is so fragmented, it is necessary to “bring the unique talents of various construction industry project participants together in a more productive and integrated manner” (Weippert et al. 2003).
Haymaker et al. (2004) describe the state of many modern AEC projects as “multidisciplinary, constructive, iterative, unique, error-prone, time-consuming and difficult”. Therefore any enabling technology should aim to address these factors. Calderon et al. (2006) agree that 3D visualisations may well improve the presentation of an architectural design, but they lack the structural detail or technical information to allow a formalized step-by-step assessment of the building’s construction, or subsequent performance. However they do enable informal analyses of the building’s visible structure that could prove to be vital. In a case-study of the Brentwood Mall Station in Vancouver, Rivard et al. (2004) found that “the 3D model allowed the architects to handle the complexity of the design, to find errors that otherwise would have been difficult to find on paper or in 2D CAD, and to prepare 3D views or 'walkthroughs' for other project parties and the public.”
Chen (2004) suggests that 3D visualisations allow a smoother bi-directional flow of understanding between an architect and a client, where previously, an architect would have been unable to successfully communicate essential design information. This is especially important early in a project, so that designs have met the approval of the client, and the wider community. During the construction of E-Commerce Place in Montreal, “a 3D model was used to do numerous urban and volumetric studies to ensure the most positive impact on the neighbourhood” (Rivard et al. 2004). The importance of this should not be underestimated, as the client’s perception of quality and satisfaction is often linked to the realisation of their prior expectations.
One of the chief drains on the budget of any construction project is the disjointed nature of the supply chain, and the misunderstandings that result from a lack of efficient information sharing along this chain (Rodgers 2001). “An average project will lose 8 to 15 percent of labour costs due to mistakes that cause change orders, delays and rework” (Sheppard 2004). According to The Economist magazine, 30% of the construction process is reworking and 60% of labour effort is wasted. There is also a 10% loss due to wasted materials (Anon 2005). Such losses are accepted by many in the construction industry, even though the cost of such mistakes is largely unquantifiable, although clearly significant, in both time and money. Problems like these are endemic in the industry within companies of all sizes, but are exacerbated by a competitive marketplace that insists on tight deadlines, and demands cost reduction wherever possible. In the case of large, highly fragmented projects, with multiple project stakeholders, investors and subcontractors, this problem is further compounded.
Trinchero (2000) describes the view taken by ‘early adopters’ (Ruikar et al. 2005) of integrated 3D project models. “The concept of project modelling is seen by many of the more innovative construction professionals as the only way to improve the record of our industry”. When 3D models are integrated into nD tools or BIM’s, they potentially have the ability to accomplish 4 key objectives of most construction projects, shown in Figure 2.2.
The issue of communication between different professionals involved in a project is of utmost importance, and in itself encourages team building. “4D models helped build synergies between the design and construction teams” (Fischer & Kam 2002). Improved communication can alleviate potential problems in the supply chain, enabling the procurement and delivery of orders at the right time. Research from Stanford University estimates that 4D CAD can help save up to 45% of change costs, leading to a minimum of around 5% overall project cost savings (Sheppard 2004). The project overview that nD CAD in particular gives, can also aid site management decisions, ensuring labour is employed on site at the correct times and places without overlap clashes. This also helps to ensure subcontractors and their equipment do not lie idle on site (Issa 2003), and that there is neither material surplus, nor shortage. 4D modelling also enables more accurate costing early in a project (Sheppard 2004). On the HUT-600 project in Helsinki a 4D model was combined with existing costing tools. There were found to be savings “of 50–80% of the work on cost estimation” (Kiviniemi 2002) and improvements in the accuracy of estimations.
Rodgers (2001) explains that a construction project is a cyclic process. However, the more accurately a project can be visualised at its inception, the less unplanned changes need to be made, leading to improved efficiency. 3D based software applications offer the potential for architects and engineers to make significant time savings during the design phase (Fischer & Kam 2002), thus leaving time to concentrate on the quality of the finished product, as opposed to spending it on failure management. The net result of this should be increased profitability (Schwegler et al. 2001). Enhanced initial design accuracy can also lengthen a building’s life cycle by minimising inconsistencies and mistakes. The chart below demonstrates the relative importance of making these decisions early in a project, by comparing the impact and cost at different stages.
A key strength of using 3D model based applications lies in their role as analytical tools. The more sophisticated tools enable in-project life cycle analyses (Fischer & Kam 2002). They provide the opportunity to analyse all the integrated data, through the functionality of the software itself, and by virtue of the collaborative, centralised use by so many varied professionals. “The advantage of this 3D object-oriented CAD system, according to the architects, is that it allows the creation of a virtual building that tracks all elements of the building, thus making it possible to manage a building throughout its life cycle” (Rivard et al. 2004). VIRCON, a now defunct UK research project, found that the integration of multiple project parameters enabled the 3D based model to act “as a communication and visualisation tool to describe the project to all parties involved in the project, and maintaining good relationship with the client (sic)” (Dawood et al. 2005). One of the strengths of 3D virtual simulations is that they can be used by large project teams seeking to analyse and assess aspects of a building’s design, engineering or lifecycle.
Issa (1999) identifies the potential to use Virtual Reality (VR) technology to promote collaboration between project partners, particularly in design creation and evaluation. Through providing a means “towards high quality dialogue where via real time experiments and visualisations a group of individuals can create common understanding and create further solutions” (Kähkönen 2003), VR offers the opportunity to improve collaboration on construction projects of all sizes. “The desirable target system is one where all those involved would have a good understanding of the building object on their own terms, at any time, and without trouble. Virtual Reality technology seems to be eminently suited to this purpose” (Kähkönen 2003). Many VR systems used in construction today are designed to allow the user “to cheaply explore design options and present visually the impact of a design prior to construction” (Moesman et al. 2004) in such a way that users, of varying professions can “prove and understand directly the performance of the built facility or environment” (Kähkönen 2003). Although smaller companies with lower budgets, which would require less functionality, tend to use VR principally at the customer interface as a ‘Wow’ factor (Whyte 2003).
According to Franklin et al. (2006) the majority of all 3D based technologies currently used in the construction industry are believed to offer three principal benefits:
- Improved design analyses through first hand cognitive interaction with a virtual building’s ergonomics.
- Improved communication between multidisciplinary project partners through mutual access to an integrated project model.
- Improved client satisfaction, through the increased opportunity for consultation regarding a building’s aesthetic choices.
The role of 3D visualisations is predominantly a conceptual one (Robins et al. 2005), more artistic than scientific. So, if visualisations only comprise a relatively small part of the design and project management processes, how valuable are they, when offset against the effort and expense required to produce them? Indeed, are the benefits of implementing 3D modelling quantifiable? No empirical study has so far been performed so far that directly compares two identical projects conducted using the alternative methods. Many of the projects that report significant cost savings, and other benefits, have been conducted by organisations that have a vested interest in the 3D product’s success, for example the CIFE/ Walt Disney Concert Hall Project (Fischer & Haymaker 2001). It is therefore reasonable to suggest that there may be some bias in their end-of-project analyses.
Any construction company considering the implementation of 3D-orientated technologies must accept short-term losses in software outlay and training costs, with potential benefits that are difficult to quantify. What many experienced industry professionals also fear is the unpredictability of the changes that seem to be inevitable to traditional construction processes. “Changes can be in terms of process automation or rationalisation, the technology can also lead to process re-engineering and formulation of new processes, which may lead to paradigm shifts within the industry” (Laudon & Laudon 2002). However Ruikar et al. (2005) find that “currently there is evidence of process improvement resulting from automation of processes”, but that there is “no evidence of process re-engineering or development of any new processes that have led to paradigm shifts”.
The information communication technology (ICT) revolution of the last decade will certainly not have passed those in the AEC industry by. “Recent surveys of IT use have suggested an increase in computer literacy in the late 1990s and 2000s, with the majority of organizations now using some forms of IT and many business processes now completely computerised” (Whyte 2003). The relative ease with which people can send information, via the Internet, is now rendering many older methods of general business communication, such as by fax or post, obsolete. ICT is quite well established in some areas of the construction industry, however more advanced tools are still some way off becoming industry standard. There are a number of reasons why this may be the case. The sceptical attitude of managers is one such obstacle. As mentioned above, there has been limited published work in construction literature to provide empirical evidence of 3D technology’s benefits. There is also a lack of best-practice models for ICT implementation in general. The list below demonstrates the fears that those in the industry consider as significant barriers to the adoption of new technology, according to the percentage of respondents who agreed.
Cost of Technology 74%
Conservative Nature of Industry 50%
Security of Hardware at Site 24%
Legal Support for Use of ICT 16%
Incompatibility/Interoperability Problems 16%
Lack of Technical Support 10%
Survey Results Related to ICT Adoption (Çiftçi 2005).
Lack of training associated with implementation, and lack of prior system knowledge is the most significant factor. The cost of investment is the second priority, due to the uncertainty over the return-on-investment. Another interestingly important area was is the security of both the hardware and the data created by the system.
As a result of these factors, many businesses will wait until they feel the tide of change is irresistible, at which point they must upgrade to remain competitive. If enough companies think this way, a ‘Catch-22’ situation may arise, the technological evolution of construction as a whole may stagnate, polarising the industry and making it even more fragmented than it already is. It is therefore important that research is undertaken to address these points in the near future. The diagram below demonstrates the cyclic effect of companies in industry either doubting the benefits of new technology or ‘putting off’ implementation, and how this could self-propagate.
This may be a significant reason for the relatively slow uptake of 3D technology in the AEC industry. It is therefore imperative that more research is done into addressing these points in the near future. Amor et al. (2002) suggest that future research should focus firmly on “compelling studies of process change, methodologies for its implementation, and toolkits for doing so”. The above theory is converse to Brandon et al.’s (2004) “tipping-point” idea, whereby the tide of industry change will eventually trigger the “accelerated penetration of information technologies into the construction industry”.
Currently there are also many issues associated with the functionality of new 3D based animation software. These are issues that could directly affect the functionality, and therefore potential benefits of such tools, once incorporated into a project. Inconsistencies such as lack of data, and level of detail which, if too small, can limit the practical possibilities for potential use in manufacturing, as well as its aesthetic realism. Too much data can slow down processing time, both in human and computational terms. There is “always the danger that the time and effort necessary to produce ever improving graphics will detract from the effort spent designing” (Vince 2003). These issues have to be addressed at the time of creating the link-up between the 3D model geometry and the design information.
Virtual Reality tools especially, are unstable and lack a dominant design (Whyte 2003). ‘Real-time’ interactive CAD applications are still very much a compromise between navigational flexibility and photo-realism (Pomaska 2004). There is still much room for improved usability, with difficulties in animating interactions between geometrical objects in a ‘realistic’ way (Kamat & Martinez 2003). Although, this is something that neither nD CAD, nor indeed the VRML file format, support particularly well either (McCarthy & Descartes 1998).
It is clear that 3D based modelling has a firm foothold in many areas of the construction industry. However, 3D based tools are still some way off becoming industry standard. The following points summarise the main findings of the literature review in relation to 3D CAD potential in today’s AEC industry:
- 3D visualisations and animations provide an effective two-way communication link between a project architect and client.
- Integrating 3D CAD into traditional practices can offer considerable time and cost savings, particularly on large-scale projects.
- The benefits of 3D CAD applications have not been demonstrated clearly enough.
- No empirical, independent study has yet been undertaken.
- There are seen to be too many, quickly evolving tools.
- Little has been done to combat common misconceptions in industry.
- 3D based tools can be viewed as too complex and expensive to implement easily.