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Get Predictive with Constructability Reviews

Posted by Patrick Krzyzosiak on Thu, Apr 23, 2015 @ 13:04 PM
Patrick Krzyzosiak
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Ever feel like you need a crystal ball to predict whether your project is constructable? Virtual design and construction (VDC) may be just what you need.

So what is VDC? VDC is the management of integrated multi-disciplinary performance models of your project, which includes the building or structure, manpower, workflow sequences and processes, and overall organization of the design and construction.  This practice references and analyzes the overall project model to determine material quantities, project schedule milestones, project cost, material quantities, as well as identifies potential project risks.  All of these elements are considered Building Information Modeling (BIM) processes.

Prior to VDC, disconnects would occur between the office and the field. Today, this practice bridges the gap between these work environments with a very proactive, more collaborative approach aimed to prevent the inconsistencies that may occur between design concepts and construction standards.  In addition, coordination and constructability reviews have now become predictive.

You may ask yourself, how?

Constructability reviews begin at the design development phase and continue through to the construction document phase.  A team, comprised of a seasoned crew of virtual design and construction professionals, preconstruction estimators, project superintendent and, if necessary, a subcontractor foreman from the trades, “begins with the end in mind.” Together, they visualize how the end product should be built.  The constructability review becomes an integral part of this process, identifying project challenges and providing solutions.  Essentially, the team performs a thorough “BIM Analysis” of the construction documents and aim to answer the following:

  1. Can the assembly be built as described?
  2. Can this assembly be built safely?
  3. Are there economies to be gained by more practical means and methods?
  4. Are there any risks and/or areas to mitigation risk?
  5. What specialty subcontractor would be required to execute and perform on this project?
  6. Are there any options to increase cost efficiencies?
  7. What are the potential changes that could erode savings gained during Design?

Reviews occur continuously along with formal reports at each pricing milestone. The objective is to always be on the lookout for opportunities to optimize and refine the designer’s intent through model. The team will suggest details and apply lessons learned from previous projects. Team communication includes model views, annotated section cuts, screen shots with markups and use of real-time visualization using Autodesk and/or Tekla latest BIM technology for collaboratively discussing issues and reaching consensus among the project team.  

Now that you have the general idea, let’s more specifically discuss constructability review at the design development and construction document phases.

Design Development Phase

During design development, VDC manages the integration of multi-disciplinary performance models. Different stakeholders, including the architect, engineers, trades, disciplines and vendors, provide models. As a result, when the models are integrated, inconsistencies in these models will need to be resolved. The effort of identifying these issues is known as clash detection. Clashes may occur between two different elements from different models that may overlap in a space. When this occurs, the team is able to analyze the clash, identify the issues, and work through a resolution.  The team may also need to identify whether the resolution will result in disruptive constructability or sequencing. The idea is to identify design conflicts in construction before building starts.

constructablity, clash detection

Clashes can be organized and defined by floor, assembly, or trade (Solibri Model Checker).

Ultimately, the constructability review team aims to provide constructability comments to the design team as progess design documents are issued. It is important to leverage the early design intent and model with construction means and methods for increased project planning. As a result, the team will then participate in a risk management meeting which will include construction cost, schedule information, construction risks and mitigation plans as needed.

constructability, design collaboration

This photo displays a high level of Constructability review collaboration WITH THE DESIGN TEAM using Revit and BlueBeam studio session.

Result:

  • Reduced construction costs through the identification and correction of clashes before construction.
  • Reduced change orders, administrative costs and processing time during construction.
  • Off-site fabrication allowing for enhanced yard management activities.
  • Increased field production by 15-20%
  • Reduced project budget and material waste.
  • Shortened, more efficient schedule.

Construction Document Phase

VDC captures all multidisciplinary models needed for construction. Together the team works to define the construction mean and methods.  In order to effectively determine the construction means and methods, constructability reviews aim to predict potential design issues to prevent construction complications.  Integrating design disciplines with construction standards will allow for a better understanding on how these systems work within the intended design in preparation for construction. At this time, co-located system issues can easily be resolved in the model as opposed to the field where these problems would ultimately result in increased project costs and time schedule.  Applying VDC with constructability review allows teams to work through these issues more efficiently allowing for reduced overall project costs.

constructability, live walk through Live walkthrough using “Revizto” software

It is not difficult to recognize the overall results for the design and construction team.

Outcomes:

  • Enables field decisions that more accurately reflect design intent.
  • Expansion of design decision-making ability with increased information accessed.
  • Delivery of more complete project designs enabling construction field efficiencies.
  • Reduce risks and rework

Example: Constructability Review - LOD 400

In the project featured below, a steel fabricator modeled the structural steel for this basement without confirming the W12x35 length located between the steel column and concrete wall. At this location, an embedded plate was scheduled to be flush to the face of this wall.

LOD 400, Constructability

Result:

Both the W12x35 steel beam was resized and an embedded plate was relocated. Similar errors were avoided and a considerable amount of money was saved. The systematic approach of BIM Analysis to review and cross reference models, drawings and specifications allowed the team to:

  • Identify inconsistencies between model elements and/or assembly and specification.
  • Ensure proposed modeled details were consistent with construction and identify opportunities to simplify or need for more detail.
  • Discovery of means and method options to meet the design intent and model element and or assembly.
  • Determine the compatibility of materials.
  • Coordinate scope between trades and verify scope gaps through missed or unaligned details between trades.
  • Understand sequencing and project scheduling by using model-based integrated construction sequencing and phasing simulations.
  • Focus on the integrity of the structure and other building systems.

VDC Quality Management

Another area to consider throughout design development and construction document phases is VDC quality management. A BIM quality plan ensures the quality of the project meets the planned one. For example, design coordination and concurrent constructability reviews should be part of your VDC and BIM quality management plan. Applying a project quality program in advance identifies the required the quality assurance tasks, roles and responsibilities and schedule.  In addition, this process identifies required tools and techniques to measure quality and performance of deliverables. It is important not to assume everyone will completely deliver the task and/or on time. The real benefit of the quality plan comes from its predictive and proactive nature.

To conclude, a successful BIM project must be managed using the following areas:

  • VDC Scope management
  • Time Management
  • Cost Management
  • Risk Management
  • Quality Management
  • Procurement Management
  • Communication management

Have you applied VDC practices with design coordination and constructability reviews? What was your experience?  Please share your story with us in the comments section!

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Topics: Constructability, Best Practice