Many people believe it’s all-or-nothing with BIM and try to make the giant leap directly to 5D. Many owners request BIM to be deployed from the project team without having a clear understanding what BIM means and how many different ways it could benefit the project.   Recently working with a project team we identified 7 different use cases:

1.) Design and Documentation model
2.) Design Coordination model
3.) Design Analysis model
4.) Cost and Schedule model (5D Virtual Construction model)
5.) Fabrication/ Shop drawing model
6.) Construction Coordination model
7.) As Built model

It is also believed that all the benefits of using BIM will be provided by building one single model throughout the lifecycle of the project. However not all project teams are ready to deploy BIM to the same extent due to process and technology issues. Parallel modeling is a meaningful first step, not only because it has the potential to include all stakeholders, but because it allows each stakeholder group to clearly express their needs for information and captures their expertise and value-add.  In addition, parallel modeling ensures that multiple teams perform a quality assurance check on all drawing sets, because the interface for information exchange stays drawing based. At the end of the day it is still the drawing set that is going to be used on the field to build the building.

Parallel models enable new efficiencies with design-assist and lean construction techniques, allowing the GC to lower and better manage construction risk.

 

1.)	The Design and documentation model is built to specifications which support design, design coordination, space planning, standard building code compliance, design visualization, creation of 2D contract document (CD) drawing sets and OSHPD submittal.
2.)	The design coordination model creates a documentation set with the help of the architects’ consultants and the design-assist subcontractors.
3.)	The 5D Virtual Construction model is used in Preconstruction and Construction for constructability analysis, extracting quantities, target cost management, schedule and task planning, organizing subcontractors and peer review of the architectural design team’s documents.

Parallel modeling allows the project team to become fully integrated, resulting in reduced and proactive management of project risk.  Parallel modeling offers a balancing point: it dramatically mitigates risk while increasing the opportunity for new efficiencies and coordination.  Each stakeholder has the opportunity to contribute their expertise and create a consumable model:

•	The architect starts with the schematic model and then evolves that model throughout the early design phase to communicate design intent  and provide a coordinated document set.
•	The contractor needs information throughout the entire lifecycle of the project and they’ll contribute a different information set such as coordination, means and methods, quantities.
•	And the sub-contractors start modeling early in the design phase and provide input for coordination and use that same model for fabrication.

Combining these three modeling approaches and building multiple models for specific use ensures a successful project and represents a winning BIM strategy for all stakeholders