Deploying 3D scanning based geometric digital twins during fabrication and assembly in offsite manufacturing

Verifying geometric compliance in offsite manufacturing (OSM) is key for ensuring adequate fit-up, structural integrity, building system performance, and assembly alignment on site. The use of a geometric digital twin (gDT) from 3 D scanning can be used to digitize an assembly to detect and resolve potential problems in a prescient manner. The contribution of this article is the development of a framework for deploying and comparing three distinct gDT approaches for use during fabrication and assembly in OSM: (1) a scan-vs-BIM approach, (2) a scan-to-BIM approach and (3) a parametric BIM updating approach. Results from a commercial building project show that scan-vs-BIM is the most accurate approach, parametric BIM updating produces the most semantically rich gDT, and scan-to-BIM is a middle-tiered option, striking a balance between representational accuracy and semantic enrichment. This study concludes that future research should develop a hybrid solution of these gDT approaches and additional more accurate measurement technologies for optimal deployment in OSM.