A maintenance system for an assembly comprises a storage medium containing an as-built computer-aided design model of the assembly, a displaying means for displaying the as-built computer-aided design model, a metrology device for measuring a location of at least one characteristic of the assembly and creating as-built data regarding the location, and a replacing means for replacing a part of the assembly with a replacement part. The replacing means determines the location for the replacement part on the assembly by analyzing the as-built computer-aided design model and the data created by the metrology device.