The journey began with hand-drawn technical figures prepared by skilled drafters. Next, computers were added to the process, which increased efficiency and improved consistency. As computing power grew, 2D lines and arcs gave way to 3D objects. All this occurred while the internet changed the way teams collaborate.
Today, we are experiencing another evolutionary step as the boundary between drafter and designer becomes blurred. With this change, many in the AEC sector are adopting a new term for design development and documentation that better captures the spirit of this next generation workflow: ‘design technology.’
To appreciate where we are today, it is important to understand the steps that led here and how each shaped the next advancement. For centuries, designers have been conveying and documenting their intent through manual drafting. Manual drafting is the process of compiling and converting design information from disparate sources into technical drawings. Unlike other types of illustrations that can have multiple interpretations, technical drawings strive to represent a single intent that produces a specific result. Over time, the profession grew into an art form as drafters learned to place an emphasis on the aesthetic to complement the technical content. However, despite centuries of refinement, drafting still possessed one major hurdle: its position in the design supply chain. It sits at the end, a final node through which all project information must flow. It becomes the place where stresses gather, and bottlenecks occur prior to delivery milestones.
The next evolution came when computers were added to the process, giving birth to computer aided drafting (CAD). The origins of CAD date back to the mid-1960s, but its true commercial impact was not felt by the AEC sector until the 1980s. Computers did for drafting what word processing did for typing. Although still relying on 2D lines and arcs to communicate, the gains in efficiency and technical accuracy were geometric compared to manual drafting.
Computers helped drafters by increasing the ease of edits and revisions, reducing the burden of repetition, improving line and text consistency, and making geometry calculations easier. The list goes on. The leap in production was also significant. Yet, despite huge advances in computing power and application functionality, CAD’s position remained unchanged – it was still at the end of the supply chain.
While the AEC sector was implementing 2D CAD, the manufacturing industry began adopting a different technology, known as computer aided design/computer aided manufacturing (CAD/CAM). Integral to this approach was the emergence of 3D solid modeling technology that was hosted on expensive computers. Unlike 2D CAD, where lines and arcs are projected representations that can easily hide conflict, 3D solids represent true physical objects in X, Y, Z space. With these tools, manufacturers began to simulate multiple aspects of reality: 3D geometry, material properties, stresses, thermal effects, and more.
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By GlobalDataThis extension of CAD/CAM became known as virtual prototyping (VP). VP shifted product development away from the iterative and costly exercise of physical prototyping to a more efficient, virtual one. This graphically rich and technically accurate environment allows users to consider more of the design earlier in the process when decisions are more fluid. VP also simulates production and identifies manufacturing problems before manufacturing begins. All this combines to add value by identifying change when change is less expensive to make.
As we entered the 21st century, the AEC sector began adopting its own version of VP based on the success of manufacturers. Our version was called building information modeling (BIM). BIM had been materializing and evolving since the 1970s, but it was not until the early 2000s that the term and the technology started gaining popularity. BIM is like VP but tuned to the needs of the AEC sector. It relies on object-oriented, 3D solid modeling technology that parametrically links design geometry to other relevant project data. In this context, ‘parametric’ means that a fixed value in one instance is a variable in another. This capability was attractive to building owners who wanted a quick means of evaluating a design in a context that concerns them.
For example, the footprint or volume of a room can be parametrically linked to the walls, floors, and ceilings that define them. Move a wall and these values change. Having the ability to dynamically link these data to prepare rent or energy use calculations became very valuable to building owners. For this reason, early adoption of BIM was found mostly in the vertical, building market and is why the ‘B’ in BIM stands for ‘building’. The successful implementation in this market led to its acceptance in others, and eventually BIM made its way underground.
McMillen Jacobs Associates’ first experience with BIM came in 2010 on a light rail tunnel project located on the West Coast of North America. BIM was an owner requirement intended to assist with the coordination of a few, targeted rooms in each of the underground stations. The scope included the use of clash detection to identify conflicts at each stage of design development.
Nowhere else was BIM specified for the project, and the design documents were to be executed and delivered using traditional 2D CAD.
In retrospect, the scope was small, but many on the team were new to the process so there was some hesitation. Upon completion of the first round of clash detection, an interesting thing happened. The team realized the value of BIM and how much easier it was to coordinate with it. Based on this experience, the team decided to go beyond the original scope and model all the station structures. To build the required drawing sheets, plan and section, views were generated from the 3D models and exported to 2D CAD files on a weekly basis. These views were also used to coordinate with other disciplines that were not implementing 3D. It became clear that coordinating with BIM, and doing so contemporaneously with design development, helped identify several potential issues earlier compared to traditional methods. BIM was labeled a success, and this experience became the basis for implementation on our future projects.
Our most recent evolutionary step occurred a few years later. It happened on a new project for the same client, but this time their BIM requirement had grown. This new requirement included a fully coordinated, multidisciplinary BIM model as a direct deliverable. This meant clash detection was to be performed everywhere, requiring that everything had to be modeled. In addition, the structural drawings were now to be produced directly from the models. This was a huge leap with respect to BIM for our company. And just like before, there was some concern and hesitation. The project was large in scope, with a fast-paced design schedule that could potentially strain the number of our qualified BIM users. It became clear that a traditional, ‘engineer mark-up to drafter’ workflow was going to create bottlenecks and ultimately impact the design schedule. To mitigate this, a decision was made to bring our structural engineers into the BIM authoring tool so that they could engage the models natively.
The intent was for them to focus on detailing to eliminate time-consuming mark-up iterations. However, as they progressed, something unexpected occurred. As comfort and proficiency grew, some of the engineers moved beyond simple mark-ups and began editing the model geometry directly. It did not take long for them to not only see the value of BIM, but to adopt it as their primary design environment. For us, this marked the first time the boundary between drafter and engineer became blurred.
A short time later, two more BIM opportunities presented themselves in McMillen Jacobs’ Central Region. The projects were the final designs of water tunnels that are part of a larger system that will provide storage and conveyance capacity to help reduce combined sewer overflow (CSO) events within a local watershed.
Although the contract did not require BIM, it did have a team eager to implement this new approach based on the success of our light-rail projects. Most of the team was new to BIM, but the West Coast staff were there to give support in the early stages and it did not take long for the value of BIM to be understood. Just like out west, as the project progressed, the engineers eventually found their way into the modeling application to handle basic mark-ups. These gave way to edits to geometry, and the engineers began to view BIM as their primary design environment. By the time the project reached final design, it was agreed that our Central Region would not deliver a structural drawing package any other way.
The quality of BIM along with the efficiency gained by engineers using it meant this was our new structural design and documentation workflow. This is a workflow we now implement no matter what the project requirements or scope.
To understand the significance of engineers adopting BIM as their primary design environment requires context. Drafting is the action of compiling and converting information. It is performed at the end of design cycles where stresses gather, and bottlenecks occur with or without the aid of computers.
The emergence of BIM marked a major improvement over 2D drafting by making conflicts harder to hide while parametrically linking relevant project data to geometry. Yet despite BIM’s capability and power, its value remains sensitive to its position in the supply chain. Handled traditionally and at the end, value still survives. However, its true potential is unlocked when BIM moves to the center of the process, where 3D models develop contemporaneously with design. This can only be achieved by those willing to break with tradition and change the way they work. It represents a new work paradigm that turns converters into facilitators and blurs the boundary between drafters and designers as engineers trade their sketches and notes for a powerful new environment.
When this is achieved, a new place is formed where design and documentation evolve holistically, parametrically, and contemporaneously. It is a place where BIM achieves its highest value and it is what we call ‘design technology’.
