By Terry D. Bennett, LS LPF MRICS LEED® AP, Autodesk

Today's civil engineers and general contractors face tight timelines and even tighter budgets, especially in the current challenging economy. To finish highway, utility, and site construction projects on time, within budget, and up to specification, they need to work accurately, efficiently, and, all too often, around the clock.

Fortunately, by combining the strengths of the building information modeling (BIM) process in both design and construction phases, and coupling that with better project delivery options, engineers and contractors can automate much of the design to construction workflow, dramatically improving productivity and accuracy, and completing heavy construction projects faster and more profitably.

Streamlining Design to Construction
BIM is an integrated process that enables professionals to explore a project's key physical and functional characteristics digitally-virtually before it is built. It uses coordinated, consistent information to design, visualize, simulate, analyze, and then document and deliver a project. Before BIM and its widespread adoption, civil engineers created designs, drafters converted them into 2D paper documents, and technicians, surveyors, and contractors interpreted these documents or reconverted them to 3D digital plans to produce lists of cuts, fills, staking coordinates, site logistics, and even fabrication instructions. This has lead to an inefficient and liability-ridden process, as written up in many industry studies, costing up to 15 to 20 percent of a project, due to one or more of the following: design errors found in the field rather than in the office, extensive redesign work through change orders, or a lack of understanding of the designer's intent by the contractors, causing requests for information and waiting days to weeks to hear back.

As infrastructure modernization speeds up globally, construction firms are having difficulty keeping up with the contracted schedules and budgets while the complexity of the infrastructure projects increases. This is combined with finding enough skilled estimators, project managers, surveyors, and equipment operators to keep these complex projects on schedule using workflows designed for projects with far less complexity. As a result, many developing countries face a labor shortage-a situation that is exacerbated by the large number of seasoned operators at or near retirement age, and the lack of enough skilled younger workers to replace them. By looking at ways to streamline the design-to-construction workflow using model-based design and a BIM process, infrastructure projects can be completed with the next-generation workers where it previously was performed only by a few seasoned professionals thereby limiting construction throughput. This change requires a new way of working that involves a higher level of collaboration-not just coordination between designers and contractors in the office, but also in the field and by starting this collaboration earlier in the project process.

Better Construction Planning in the Office
Traditionally, design data created by the civil engineers has been somewhat isolated and fragmented from the rest of the project team. What they created very often would not move across to the contractors nor was it intended to do so. Contractors were expected to create their own set of information separate from the engineer, and there was no easy way to close this gap-one that could enable the rich design information to cross over to the construction phase, let alone address the legal framework by which it could happen. In addition, the ability for the contractors to impart their years, if not decades, of construction knowledge into the design process was not previously possible since many designers never knew which contractor would be selected to do the construction. And even if they did, there was really no interface in the design process where contractors could plug in.

BIM changes this. The process and its collaborative visual/analytical nature de-risks projects by making outcomes far more predictable and with a reduction in errors, increasing margins. BIM produces component-based construction models that enable the virtual construction, sequencing, and operation of infrastructure as part of the planning and design phase. BIM helps enable optimization of a design, to compare and contrast various approaches to sustainable designs with associated lifecycle costing, and when a concept is approved, it provides the foundation for construction sequencing and field operations. The benefits of a BIM process for heavy contractors working collaboratively with designers include:

Communicate design intent during planning, zoning, and public involvement meetings.

Visually explore the engineer's designs with them clearly and accurately before construction:

• Integrate 3D models of all trades for clash detection/avoidance and constructability issues before they materialize in the field
• Detect errors where they are less costly to fix using constructability analysis
• Collaborate with extended project team stakeholders including:
  -Subcontractors
  -Local utilities
  -Owners
  -Municipalities

• Ensure "currency" of models
• Reduce RFI/change orders

Accelerate the decision-making process by visualizing/analyzing project parameters to support:

• Estimating takeoff-balancing cut/fill volumes
• Project environmental impact
• Infrastructure lifecycle cost analysis
• Heavy construction time/scheduling
• Carbon impact
• Maintenance requirements (roads, water, sewer, drainage)
• Shop drawing production and prefabrication of infrastructure components

Visualize construction logistics to review and optimize construction sequencing and schedule:

• Lane closures
• Utility outages
• Trade sequencing (bridges, drainage, sewers)
• Equipment and material schedule optimization
• 4D (time); 5D (cost) planning

The BIM process and its design models become the single truth of design for planners, engineers, contractors, fabricators, and commercial and operational managers. It enables optimization of the design in terms of function, time, and cost; and by virtually constructing the infrastructure, coordination is achieved before work is started on a site. The construction sequence is streamlined.

Better Construction Project Execution in the Field
One of the ways in which model-based design and a BIM process in the office is having a big impact in the field and construction execution is GPS machine control. It has begun to revolutionize the heavy construction industry in many regions of the world and will continue to do so in other countries by making it possible for contractors to complete projects faster, within budget, and to a much higher degree of accuracy. In fact, using GPS machine control technology with laser leveling and a model, contractors can match a design engineer's specifications to within millimeters in the horizontal position and centimeters in vertical position and help deliver:

Time savings: Construction crews can operate 24/7 without having to wait for staking, cut sheets, and crews.

Safety: No one is in harm's way while the machines are operating, as no one is required to set grade stakes.

Cost savings: Engineers save time during the modeling process, and contractors save time in the office and in the field.

Green design: More efficient operation results in reduced material use and waste, lower fuel costs, and more accurate outcomes.

Other benefits for contractors in the field being realized using a BIM process includes:

Accuracy: From design model to field, teams can greatly reduce interpretation/interpolation errors and costly rework.

Better jobsite management: The single, real-time model and user-specific views enable much better interrogation of design and accurate, real-time documentation of everything your crew does.

Construction sequencing: Users are able to sequence construction, equipment, and materials and track progress against logistics and timelines established in the office by use of laser scanning for up-to-date as-builts.

From Coordination to Collaboration and Constructability

As previously discussed, BIM provides great value to contractors, helping them achieve success by modeling for constructability in the office and using that information in the field to drive the physical construction process. But the value does not stop there, and can be extended even further if desired. Automating the workflow of design to construction is one step, but if designers do not or will not share the models with contractors due to liability or legal reasons, the process will often come to a halt. Industry experts have worked together to develop several new project delivery methods that address risk and liability, licensing, and usage rights for the distribution of digital data, such as models from BIM. Most prominent among these new approaches is integrated project delivery (IPD). IPD is "a project delivery approach that integrates people, systems, business structures, and practices into a process that collaboratively harnesses the talents and insights of all participants to optimize project results, increase value to the owner, reduce waste, and maximize efficiency through all phases of design, fabrication, and construction."

IPD stems from current challenges facing the design and construction industry, the need for a more holistic view, and understanding of the project from three key perspectives: the designer, the contractor, and more importantly, the owner. This is partly driven by industry history and past experiences but also by no one discipline truly "knowing" all the intricacies of a project and having a holistic view of the project. In fact, many seated at the table do not have the perspective of what is required for successful project execution across all disciplines or how their decisions may impact others. They only understand it from their unique perspective.

IPD is based on Australia's approach to project delivery, project alliancing (PA). PA was created for the delivery of high-risk infrastructure projects, where risks were unpredictable and best managed collectively. This approach has been used on more than $32B worth of civil infrastructure in the past 5 years, $8B alone in 2009. The framework enables project contributors to focus on the design problem, rather than litigation prevention, taking the approach of mitigating issues first and foremost not litigating them.

Using models and a BIM workflow to facilitate discussion on the design are an ideal complement to this delivery approach. BIM is a technology process, whereas IPD and PA are behavioral processes that enable teams the legal umbrella and framework to foster better collaboration and set the stage for more efficient design and construction process overall.

Conclusion
With all of the recent advances in design and construction modeling technology and a workflow centered around BIM, it is no longer a question of whether civil engineers and contractors are going to adopt this new, more efficient, and more profitable way of completing heavy construction projects. It is only a question of when. In today's challenging fiscal environment, streamlining your business and increasing efficiency is crucial. The adoption of these technologies is still a powerful competitive differentiator. Early adoption of these exciting new technologies and processes can also help ensure that your company will not only remain attractive to young talent that can help your firm prosper far into the future, but it can also help to expand your ability to deliver more complex projects on time and on budget with better predictability.

Terry D. Bennett, LS LPF MRICS LEED^® AP, is the senior industry manager for civil engineering and heavy construction at Autodesk and holds worldwide responsibility for the company's industry strategy and relations in the areas of land/environmental planning, land surveying, civil engineering, and heavy construction. Over the past 24 years, as an industry strategist, he has presented at numerous conferences worldwide and published many articles in industry trade magazines on the impact of technology and sustainable approaches to the AEC and geospatial industries. He currently sits as a Governing Assembly Member of ASCE's PERSI (Practice, Education & Research for Sustainable Infrastructure) initiative, is a founding editorial board member of Rebuilding America's Infrastructure magazine, and is a member of the Urban Land Institute's Public Development & Infrastructure Council.

Autodesk is a registered trademark of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders. Autodesk reserves the right to alter product and services offerings, and specifications and pricing at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document. © 2010 Autodesk, Inc. All rights reserved.