Abstract: A method of reducing performance deviation in at least one additive manufacturing apparatus during production of parts is provided. Each apparatus has a light source configured for polymerizing a light polymerizable resin with sequential doses of patterned light to produce a 3D object. The light source has an assigned nominal emission data, such as an expected or preset standard emission data, and actual emission data. The method includes modifying at least some of said light doses in said at least one apparatus during production of parts therein to compensate for a deviation of said actual light source emission data from the assigned nominal emission data.