A laser scanner makes a virtual point cloud model of the area that it scans. These point clouds are typically made into solid 3D models that can be viewed on any computers. Both the models and the point clouds are in scale and can be used to find dimensions. This makes it possible to sit in an office onshore and for instant find a suitable pipe routing, so exact that the whole line can be prefabricated in a workshop. The same applies for structural modifications or new installations.
When a pipe line or a structure is designed, it can be placed into the point cloud to verify that it will fit. Any obstacles will then be discovered. One can also determine how the new structure will fit according to existing beams and stiffeners and therefore be a good tool for the structural calculations.
Laser scanning is a tool that reduces the need for surveys and reduces the time for engineering. It allows for more prefabrication that reduces the time for installation. This is why laser scanning is becoming very popular and used in almost all large rig projects.