Not that many years ago, few structural engineers were aware of building information modeling (BIM) and they could not have imagined the dramatic change it would bring to the AEC industry. Today, some structural engineering firms have made impressive strides toward implementing BIM as their primary production platform while most have at least investigated how this new technology of 3D modeling of the building structure will affect their product delivery. Much has been written about the potential of BIM and how it can improve the design process, but the most profound impact on a structural engineering firm implementing BIM is on the roles and workflow of the staff.
Integrated project delivery leveraged the 3D structural model on Seattle Children’s Bellevue Clinic to bring team members together for visualization and coordination. Further expanding the benefits of BIM is the utilization of integrated project delivery (IPD) to effectively create a unified team with the owner, design team, and contractors. The advent of the IPD process will bring even more changes to workflow and roles. IPD restructures the delivery process so that all team members are on an equal footing contractually and allocates sharing the risk and reward of design and construction. The mechanism that facilitates communication, visualization, and collaboration between all team members is the shared 3D model and the power of its parametric database.
Traditional workflow and design process: The paradox of our profession is that while we conceive a structure in the 3D realm, our deliverables are normally produced as 2D paper drawings. Whether 2D CAD or ink on Mylar, the finished product for structural engineering firms has historically been a set of drawings with lines, arcs, symbols, and text that represent the original 3D concept. These drawings then serve as a contract document for a general contractor to interpret back into a 3D reality during construction. The real potential for BIM is to utilize the power of the 3D model for collaboration and visualization in as many aspects of design and construction as possible.
The traditional workflow of a structural engineer’s office has been established over the years to efficiently produce a set of high-quality structural drawings that are well coordinated with the drawings of the architectural client and fellow consultants. The process begins with principals and project managers conceptualizing the structural system and then conveying the design to project engineers who follow through with analysis and structural detailing. Analytical 3D models are often utilized for structural system design, but seldom have a direct connection to the 2D drawings. Projects are typically phased into increasingly developed design levels with 2D drawing sets acting as the deliverable product.
These drawings are produced in most offices by skilled technicians utilizing CAD software to reflect the design intent onto 2D drawings. Throughout the process, the engineers provide review and quality control, typically with colored pens and highlighters on check prints. Documents are plotted at each phase and ultimately serve as the basis of a contract set used by a general contractor to prepare his bid and construct the building. Architectural, structural, civil, and MEP drawings are manually interpreted and cross referenced to coordinate the entirety of the building’s systems. This process has been honed and refined into an effective system for conveying the information necessary to construct a building.
Firm integration of BIM workflow and process: BIM necessitates a paradigm shift in the methodology and workflow of a structural engineer’s office and fundamentally moves the functional deliverable from 2D drawings to a 3D model. While 2D drawings will remain the legal instrument of service for the foreseeable future, the 3D model will be the vehicle by which the structural engineering firm will convey the structural intent to the rest of the design team and ultimately to the general contractor and owner. Implementation of BIM in a structural engineering firm is challenging beyond the cost of the software, hardware upgrades, and training. In the traditional 2D workflow, roles for a firm’s team members were clearly identified and time tested for efficiency and product quality. The new paradigm of using BIM blurs the line of who is most suited for creation and updating of the model. Traditional roles need to challenged and the most effective implementation requires buy-in at all levels of the firm; consider the following new roles:
Project managers and principals may not spend a lot of time modeling, but their experience must be leveraged for the BIM process to be successful. They must be able to access the model for review, QA/QC, and be able to communicate fluently with owners and architectural clients. Maximum efficiency utilizing BIM can only be realized by working directly in the 3D model and not continuously moving back and forth between the 2D drawings extracted from the model. As the sophistication level increases with the design team’s use of BIM, the 3D model becomes the actual design and coordination tool and the 2D drawings become less significant during the design process. The use of 3D screen capture of the model and electronic mark-ups should be used extensively to expedite revisions to the model.
Most design and project engineers have grown up with computers and feel at home in the 3D environment. However, virtually constructing a building in BIM requires the input of an experienced structural engineer who has seen many buildings go together and understands how structural systems interact with other disciplines’ systems. Teaming junior and experienced engineers — while using BIM for the layout of the framing system — provides the ideal mentoring opportunity for engineering design as well as 3D model building.
Drafters in structural engineering firms have traditionally operated as production technicians who transcribed detail sketches and “red-marked” plans from engineers into contract documents while following firm standards for drawing production. The move to BIM requires the technician to have a solid understanding of the actual construction process to be able to create a model that accurately reflects what will be built in the field. Their ability to communicate effectively to the engineer how the model is evolving and changing through each phase of the process will be instrumental in the success of the project. The need to understand the structural model as well as the requirements of the architect and other consultants increases the drafter’s role as an important project team member.
As a key part of our transition to an all-BIM production environment at PCS Structural Solutions, we have developed a BIM Abilities Matrix that analyzes team member roles, identifies the BIM skills necessary, and to what extent each member of the firm will need to be trained to utilize the model most effectively. The matrix also acts as an evaluation tool to determine how individuals are progressing toward learning their applicable BIM skills. A formalized in-house training process called PCS University addresses the needs for each level of responsibility and provides the skill sets required. These classes were set up taking advantage of numerous resources including firm-wide expertise in analysis, modeling, and detailing in BIM.