3D/CAD Link (Archived)

RT-106 Topic Summary
RT 106

Overview

The use of three-dimensional computer-aided design (3D CAD) in construction and construction management was identified by the Construction Industry Institute as an important area to investigate because of potential benefits to the industry. Work done in the past in 3D CAD has provided little substance into the exact nature of the value of using this technology. In addition, little guidance exists about how to achieve the best value of using 3D modeling. CII, therefore, created the 3D CAD Link Research Team (I-106) and asked that it determine the benefits of and the impediments to using 3D in construction.

The 3D CAD Link Research Team’s original mission statement included the following scope and objectives:

Scope

  • Survey of 3D computer models in construction to identify costs, benefits, penalties, and rewards
  • Study indicators that firms use to measure impacts associated with using 3D computer models on site
  • Perform a case study and establish firm costs and impacts in the use of 3D computer models throughout the construction cycle

 Objectives

  • Develop a framework for categorizing and measuring impediments and benefits of the use of 3D computer models in construction
  • Develop firm, explicit cost impacts on an actual project                                          

Key Findings and Implementation Tools

1 : 3D CAD Common Applications

The research found that the construction management applications currently being performed with the assistance of 3D were most commonly used to check clearances and access, to visualize details from nonstandard viewpoints, and to perform constructability reviews. Impediments to the use of 3D included undetermined economic impacts, a resistance to change within the construction industry, and a lack of trained personnel. (RS106-1, p. 30)
Reference: (RS106-1)

2 : Industry Applications and Benefits

The benefits from using 3D CAD technology were clear and conclusive, and indicate that increased usage of 3D CAD can provide significant reductions in cost growth, schedule slippage, and total rework. Aggressive and broad use of 3D CAD technology can bring repeatable benefits provided that the user is willing to invest time and resources in becoming adroit with the technology.

Figure 15 shows the Use of 3D Models vs. Project Costs and confirms that the 3D models are more likely to be used as the cost of the project increases. This graph makes intuitive sense in that one would expect the benefits in using 3D computer models in construction to become more pronounced in more complex, costly projects.

According to the results of this research, the more ways that the model is used on site, the greater the benefits in the project’s outcome can be expected. This may simply reflect the level of expertise of the users, but is significant nonetheless. It also is interesting to note that virtually all of the comments received in the surveys indicate that the use of 3D computer models in construction can be of great benefit and that their eventual acceptance as industry standard is inevitable.

Having taken all of this into account, it is still quite clear that the projects that used the 3D computer models effectively during construction experienced significant benefits. In addition to their outcomes being more predictable, these projects experienced the following benefits:

  • Five-percent reduction in cost growth
  • Four-percent reduction in schedule slip
  • Sixty-four-percent reduction in project cost due to rework
(RS106-1, p. 11)
Reference: (RS106-1)

3 : Case Study Project Applications

A detailed case study was performed by RT-106 to substantiate these benefits, and is described in summary fashion in RR106-11. The case study supports the value of 3D CAD improving performance for several site functions. (RS106-1, p. 13) 

The site personnel used the 3D model in a variety of applications, including:

  • Checking clearances and access
  • Sequencing construction activities
  • Constructability reviews
  • Reference during project meetings
  • Interference checks
  • Answering queries by contractors
  • Visualizing details
  • Work package definition
  • Exchanging information with a vendor
  • Estimating costs for late scope additions
  • Locating installation points
  • Tracking construction progress
  • Recording as-built conditions
  • Training personnel

The construction staff indicated several issues that were critical to the successful implementation of this 3D computer model on site:

  • Good support from the head office design staff during construction
  • Frequent (daily) updating of the model
  • Having personnel on site with training and experience in the use of the model
  • Easy access to project database through the model’s graphical interface

The construction staff also identified several areas that could be improved in future applications of the 3D model on site:

  • More complete modeling of existing utilities before construction
  • Locating a workstation closer to the construction work (200 yards to walk to the workstation can discourage optimum use)
  • Improve the ability to extract quantities of bulk solids (concrete) in the model (This is a software-specific issue that has been corrected.)
  • Reduce the learning curve for new users by improving the user friendliness of the interface and documentation available
  • Improve the use of the model by the contractors without the assistance of owner personnel (i.e., better training for contractor personnel)
  • Expand the functionality of the system to incorporate holograms and/or virtual reality
Reference: (RS106-1)

4 : Owner/Contractor Perspective

It is clear that the future of the process and power construction industry will include 3D computer models. So what is the appropriate strategy with which to approach the implementation of this new technology within your company? The answer depends upon your perspective. (RS106-1, p. 20)

Owners
  • Owners need to approach the use of 3D computer models on their projects with caution. Hiring an EPC contractor who does not know how to use the technology effectively can be a mistake. The team’s analysis show that the improper use of 3D on a project can lead to an outcome that is worse than if the traditional 2D drawings and plastic models were used.
EPC Contractor
  • EPC contractors who are not making the transition to 3D will have severe problems competing in the process and power construction industry in the near future. The industry leaders are all in various stages of development in this area, and those that have not started will be at a greater disadvantage as time goes on. The commercial and infrastructure construction industry will take considerably longer to assimilate this technology. Companies that have extensive experience and a proven track record will have a significant advantage.
Reference: (RS106-1)

Key Performance Indicators

Improved cost, Improved schedule, Improved quality (reduced errors & omissions), Improved design

Research Publications

3D CAD Link - RS106-1

Publication Date: 11/1995 Type: Research Summary Pages: 34 Status: Archived Supporting Product

An Analysis of the Impacts of Using Three-Dimensional Computer Models in the Management of Construct - RR106-11

Publication Date: 09/1995 Type: Research Report Pages: 228 Status: Archived Reference


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