An abundance of research focuses on the collective performance and motivations of the TEAM in BIM coordination and execution. The team, however, consists of trade partners with different motivations and sophistication. Trade partners whose product is directly fabricated from 3D models, such as mechanical and steel contractors, are highly sophisticated in BIM. Their models tend to be accurate and vetted for constructability as their profitability depends on quick onsite assembly of prefabricated items. Trade partners whose work installation is not directly fabricated from 3D models tend to have less accurate models that are not vetted for constructability. Non-constructible elements included in BIM are waste as they do not bring value to the intermediate or end user. More perniciously, these models are a presentation of inaccurate information in a highly detailed form, leading to the perception of accuracy and the incorrect detailing of adjacent assemblies. This paper uses case studies of BIM implementation in the San Francisco Bay Area to analyze model accuracy and implementation by trade and identify best practices in team alignment. This analysis is used to propose a framework for enforcing model constructability based on the basic tenets the Last Planner System™. Beyond project controls, this paper investigates natural alignment of trade interest in constructible models. Specifically, if a trade partner’s profitability is increased through the use of model-based layout or increased off-site fabrication, the model will consequently be more accurate, benefiting the larger team. Therefore, this paper also discusses the advantages of intrinsic motivation to reduce variability of trade models between coordination and the field, and proposes methods to achieve this future state.
BIM, Constructability, Last Planner™, Buildability