Identification of Data Items Needed for Automatic Clash Detection in MEP Design Coordination

Abstract

This paper discusses a study carried out during the mechanical, electrical and plumbing (MEP) design coordination of a 210,000 square feet facility, currently under construction in Western Pennsylvania (Project X). We have compared types of clashes identified in their manual coordination process (overlay of 2D drawings on a light table by pairs of subcontractors) and through automatic clash detection using a building information model (BIM) in NavisWorks JetStream v5. The automatic clash detection identified several clashes that were missed by the subcontractors, who were performing this task manually. Also, the manual clash detection identified clashes which could not possibly be found by the automatic clash detection software, since one of the clashing objects (e.g. cable trays) was not modeled in the BIM. This study also included site observations of field detected clashes, some of which were not identified in either manual or automatic processes. Results show that the combination of clashes identified in coordination meetings, those automatically detected, as well as those identified in the field enable identification of objects that need to be modeled in order to capture the largest possible number of clashes. This paper was limited to the comparison of types of clashes identified in each of the three methods during a specific project. Although these results cannot be generalized, they still provide insight towards the need to identify what needs to be modeled in a BIM for MEP coordination prior to the start of the coordination process.