1. A computer-implemented method of 3D Computer Aided Design (CAD) modeling comprising: receiving laser scan data of various equipment within a subject facility, the various equipment having a use associated with the subject facility, there being a prior generated 3D CAD model of the subject facility; applying a computer automated analysis to the received laser scan data to rebuild the 3D CAD model of the subject facility, the computer automated analysis utilizing design logic of the subject facility and design logic of the equipment of the subject facility, wherein the design logic of the subject facility is a plurality of rules expressing how equipment of the subject facility interacts with other equipment of the subject facility; and updating the design logic due to different locations of objects which were identified in the prior generated 3D CAD model of the subject facility and captured by generating an exception rule and implementing the exception rule as one of the plurality of rules to systematically knowledge capture the object and therefore update the practical implementation of the object; wherein applying the computer automated analysis further comprises identifying in the received laser scan data a shape of the equipment of the subject facility defined in a graphical object database and mapping the identified shape to a CAD modeling primitive within the graphical object database; and said identifying includes iteratively identifying sub-shapes in the received laser scan data, and mapping the identified sub-shapes to a CAD modeling primitive within the database until an identifiable shape is created; and rebuilding the 3D CAD model of the subject facility based on the computer automated analysis.