The Future of Model-Based Design

Many things have changed in the engineering industry during our lifetimes. The personal computer revolutionized the production rate of drawings, networks have fundamentally changed the way we store and share information, and the amount of information engineers put out to bid for a project has steadily increased. 

Since the early stages of 3D modeling in the 90s, engineers have envisioned a time when traditional plans would no longer be needed. A time when we could design infrastructure entirely in 3D and then directly bid a 3D model, has felt like a pipe dream to most in the industry. The idea of controlling engineering intent entirely through 3D models is often referred to as BIM (Building Information Modeling). This is largely because the sectors of the infrastructure market that used 3D first were controlled and included factories, multi-story buildings, and power and utility plants. Infrastructure with connection to the real world was effectively limited to finished floor elevations and utility connections.

A view from the Infraworks model created for the intersection of I-90 and I495.
It is a view from I-90 eastbound looking at one of the ramps from I-90 to I-495.

Since the turn of the century, civil engineers have increasingly relied on 3D models to accelerate plan production, but largely maintained a traditional control of engineering intent. Model-Based Design (MBD) is the transition to controlling engineering intent through the 3D model, which is significantly different than just using a model to accelerate production plans.

A good example would be the design of a retaining wall along a roadway. A traditional engineer’s process might be to extract some elevations from the existing ground and proposed roadway profile, complete the design in a spreadsheet, and then manually create the 3D model of the wall to be displayed in the plans. An engineer using MBD would look at this problem differently. By programming the constraints for the retaining wall into the model, the model reacts to the elevations of the ground and roadway profile along the project. It’s the transfer of engineering intent from the spreadsheet to the model that marks the distinction between MBD and traditional engineering methods. This is profound for several reasons:

• MBD focuses on a single source of truth for a project—the model. This reduces risk and improves accuracy design outcomes. 
• MBD utilizes the full capabilities of modern design software and automation, saving time and money during the design phase. 
• Models serve as an indispensable communication tool, both for internal engineering teams and external communications with owners and the public. 
• Models are necessary to realize many of the benefits of digital twins, including design review, construction management, and operations. 

VHB recognizes that the future of civil engineering is model-based. MBD is a movement that is on par with the personal computer and internet in the sense that while it won’t change engineering principles, it will change how we engage engineering principles to deliver infrastructure projects. 

Aerial view of the Infraworks model for the I-90 and I-495 interchange. This
view is able to give a visual of the changes to this complicated interchange.

Our clients are increasingly adopting 3D standards and requiring 3D delivery for construction bids, while software companies continue to make rapid improvements in the capabilities of design tools. As the industry continues to pick up the pace of the design process, our clients also want a more detailed analysis earlier in the process. For example, property management companies want to know if a site will require significant grading or walls before they even purchase the property. VHB uses models to demonstrate the design while also being able to leverage the information to perform conflict analysis, grading calculations, phasing, and visualization of the design to give our clients the confidence to move forward with the design or visualize changes that need to happen. 

The model also serves as a digital twin to a project by allowing us to communicate complex design challenges in an easy-to-digest way. For those that may struggle to understand 2D plans, the digital twin allows for quick comprehension and timely feedback. With a model, we can enhance the visual experience for community members and the digital twin can be used to show the community the impact a project will have in their neighborhoods. 

Not only does the model help with communication in our communities, but with other consultants as well. VHB can work more efficiently and reduce risk when we can integrate our models with those of architects, subconsultants, and mechanical, electrical and plumbing engineers.

For a real estate client, VHB prepared this development analysis using
a model-based design that incorporates property boundaries,
setback limits, and GIS data.

At VHB, we are embracing MBD and recognize that for large-scale change to happen, education is critical to success.  VHB is invested in firmwide MBD training for its CAD users, as well as a next-level training program for advanced MBD users and future trainers, that will assist with our modeling initiatives.

Currently not all VHB clients are using the modeling process, but we're seeing the advantages of how MBD can make improvements for all projects, big and small, and the benefits from the MBD approach. While this integration isn’t going to happen overnight, VHB is committed to this collaborative design experience and other technology-enabled solutions.