The prospect of a full-scale BIM implementation within a general contracting firm can seem daunting, so why not start with 3D coordination using Autodesk® Navisworks? Implementing just this workflow can provide a sizeable return on your investment while keeping implementation manageable. Through careful planning, program definition and training, the implementation of a Navisworks-based 3D coordination program is a relatively cost-effective way to enhance the execution of any construction project. This article will outline a few key points to make your implementation a success.
Possibly the most important key to success is defining a reasonable scope. Don’t take on more than your firm can reasonably accomplish. Pick a relatively simple project with strong MEP subcontractors as a pilot to develop your program. Define what your desired outcome for the coordination effort looks like. It could be a reduction in the number of RFIs found in the field by a certain percentage or to have the trade contractors produce installation drawings for their work. Outline what the benefits will be to your business and who will make up the implementation team. Also essential is planning a lessons learned meeting after the pilot project so that valuable lessons won’t be lost. Finally formalize and write all of this into a project charter. This document will help guide you through implementation and keep you focused on accomplishing your primary goals without taking on additional scope.
The next step is to formally define your BIM program. There are a few important documents and protocols that are a must have, and arguably the most important is creating a hardware specification document that provides adequate computer hardware for you to utilize Navisworks and other 3D products to their full potential.
Defining and communicating the rules of engagement before the start of a 3D coordination is critical to success. A BIM Requirements Document (BRD) can be used to describe and mandate how the models and team will interact with each other. It will define who participates in the coordination process, and what is required of them. A typical BRD will include specifications on shop drawings, level of detail (LOD), frequency of meetings, and a method of signing off the Navisworks NWD model once all coordination issues have been resolved. The AGC BIM Forum document, MEP Spatial Coordination Requirements for Building Information Modeling is a great starting point for any BIM program.
A clear definition of file naming and archiving protocols are must haves when running 3D coordination through Navisworks. Creating a system that is aligned with the Navisworks Clash Detection process will make updating Clash Detection batches seamless. Carefully documenting naming conventions and archiving processes will help you to make sure that everyone on your team is accountable and committed to making the Clash Detection process as seamless as possible. This is extremely important as you will likely have to keep track of multiple iterations of models that must maintain the same filename from each trade partner.
Model coordination sequence guidelines can help speed up the coordination efforts significantly as well. These guidelines define general parameters of what systems take precedence when considering what model elements should move in order to resolve Clash Detection issues. Reaching consensus on these parameters can greatly help your relationship with your trade partners. These guidelines can be enhanced by using Navisworks to colorize the model items according to your model coordination sequence. Though these guidelines are no substitution for collaboration and good judgment, by defining general guidelines for model coordination sequence, you can empower your trade partners to manage and resolve relatively low impact items on their own so you can spend more time managing higher impact items that may require input from the design team or have potential cost impacts.
Figure 1: Model sequence colorization.
The last key to implementation is the development of a software training program. Being efficient in both AutoCAD® and Navisworks will not only reduce the overall cost of coordination, but will reduce frustration as well. Keeping in mind that your training should be relevant to the scope of your implementation, you should initially focus on the key items that you need to effectively run a coordination effort. If you are just starting out, that might be a bit difficult as you might not be exactly sure where to start. I’ll outline the key areas of AutoCAD and Navisworks that will provide a solid foundation for a successful 3D coordination program.
A solid understanding of AutoCAD is important to being proficient in Navisworks because the origin (0,0,0) in AutoCAD determines where each trade model will be inserted into Navisworks. Most of your trade partners will be submitting models to you in DWG format (the file extension for AutoCAD files). These files will need some reference point to align to, which is commonly referred to as the insertion point. If this point is not established ahead of time, models will often not align correctly making 3D coordination impossible.
A good practice is for the GC to provide an AutoCAD background for the trade contractors to reference which seamlessly provides a common insertion point. Adequate training on this concept will help you troubleshoot and hopefully eliminate a common problem that is completely unnecessary.
Figure 2: Insertion point wasn’t understood by Fire Protection contractor.
In Navisworks, proficiency in navigating the model, aggregating clashes, and searching the model are essential to running an effective coordination project, and Navisworks provides extremely powerful tools to accomplish these tasks. Concentrating your training efforts on at least these three areas will maximize your return on investment by reducing the overall time spent in coordination.
Concentrating training time in navigation will help you get through coordination meetings efficiently by getting to each issue faster. If you have ever participated in a coordination meeting, you have most likely witnessed bad model navigation and its negative effects on meeting duration and audience engagement. Considering that hundreds, if not thousands, of clashes and issues will be found during the course of a project and each one will have to be navigated to, and examined, so even a savings of a few seconds can create a big impact on meeting productivity.
Learning to interrogate and parse the model using the search set functionality of Navisworks is another incredibly powerful tool that can be used to provide meaningful clash results. Through search sets you can run Clash Detection discrete portions of the model to drill down into just the issues that are relevant at the moment. For example, with search sets you could potentially drill into a plumbing model to perform clash detection only on gravity-fed items rather than the entire system. This functionality can help you examine the BIM at a more granular level, potentially allowing you examine more specific issues by filtering out a large volume of clashes that aren’t of equal impact at that point in coordination.
Finally, learning to aggregate and process large amounts of clash data is essential to the timely completion of a coordination project. You can reduce the overall cycle time of model upload to coordination meeting by focusing your training time on the Clash Detection aggregation functions. Due to the large amount of “duplicate” clashes, and the way Navisworks sorts Clash results by severity and not location, it is essential to master their aggregation tools. Mastering the use of simple but powerful features such as Select Filter to roll several related clashes into a clash group can not only cut down on meeting duration but can also make navigation to issues more effective.
Figure 3: Using select filter can aggregate multiple clashes into one concise issue.
Even though a full-scale BIM implementation including tie-ins to scheduling and estimating may not be feasible for most firms, a focused implementation centered around Navisworks 3D coordination can provide immediate returns for a modest investment in software, training, and staff.
Jesse Ocon is the Director of Virtual Design and Construction (VDC) at Scenario Virtual Project Delivery with responsibility for the implementation of strategic innovations of construction technology. Prior to joining Scenario Virtual Project Delivery, Jesse developed the BIM/VDC program for Erickson Construction Co. In his current role, Jesse leads the implementation of Lean Process Management and focuses on developing strategic alliances with industry partners. In 2011, he certified as a Lean Six Sigma Black Belt and became a member of the American Society for Quality (ASQ).