A method, apparatus, and computer program product for identifying gaps. A grid of points is generated on a first surface. The grid of points is associated with a point for a first part associated with a second part in a model. A line segment is formed from the first surface of the first part to a second surface of the second part for each point in the grid of points to form a plurality of line segments. A gap size is identified between the first surface and the second surface using the plurality of line segments to form a plurality of gap measurements.