A method carried out by a controller for determining a set of additive manufacturing parameters comprising: a) determining a nominal parameter of at least one surface (20, 30, 40, 50; 120, 130, 140, 150) of a nominal component (10; 100), wherein the nominal parameter is a surface roughness of at least one surface (20, 30, 40, 50, 120, 130, 140, 150); b) determining at least two second order variations in said nominal parameter, wherein the at least two second order variations comprise variations that are not accounted for while determining the nominal parameter of the nominal component, the at least two second order variations including powder perturbations during an additive manufacturing process, powder particle size variations, orientation of the part during the additive manufacturing process, power source variations, beam profile, orientation of a sintered surface relative to prior and subsequent sintered surfaces; c) predicting an actual resultant dimension based at least in part on the nominal parameter and the at least two second order variations; and d) adjusting at least one additive manufacturing process parameter in response to said predicted actual resultant dimension; re-iterating steps a) to d) until the predicted actual surface roughness is within a range of acceptable actual surface roughnesses, and storing a set of additive manufacturing parameters determined in a last iteration of steps a) to d); wherein predicting an actual resultant dimension based at least in part on the nominal parameter and the at least two second order variations comprises determining an expected effect of the at least two second order variations on the nominal parameter; and wherein determining an expected effect of the at least two second order variations on the nominal parameter comprises applying: probabilistic distributions of the at least two second order variations to the nominal parameter; mechanistic distributions of the at least two second order variations to the nominal parameter; and/or mathematically determined physics distributions of the at least two second order variations to the nominal parameter. a) determining a nominal parameter of at least one surface (20, 30, 40, 50; 120, 130, 140, 150) of a nominal component (10; 100), wherein the nominal parameter is a surface roughness of at least one surface (20, 30, 40, 50, 120, 130, 140, 150); b) determining at least two second order variations in said nominal parameter, wherein the at least two second order variations comprise variations that are not accounted for while determining the nominal parameter of the nominal component, the at least two second order variations including powder perturbations during an additive manufacturing process, powder particle size variations, orientation of the part during the additive manufacturing process, power source variations, beam profile, orientation of a sintered surface relative to prior and subsequent sintered surfaces; c) predicting an actual resultant dimension based at least in part on the nominal parameter and the at least two second order variations; and d) adjusting at least one additive manufacturing process parameter in response to said predicted actual resultant dimension; re-iterating steps a) to d) until the predicted actual surface roughness is within a range of acceptable actual surface roughnesses, and storing a set of additive manufacturing parameters determined in a last iteration of steps a) to d); wherein predicting an actual resultant dimension based at least in part on the nominal parameter and the at least two second order variations comprises determining an expected effect of the at least two second order variations on the nominal parameter; and wherein determining an expected effect of the at least two second order variations on the nominal parameter comprises applying: probabilistic distributions of the at least two second order variations to the nominal parameter; mechanistic distributions of the at least two second order variations to the nominal parameter; and/or mathematically determined physics distributions of the at least two second order variations to the nominal parameter. re-iterating steps a) to d) until the predicted actual surface roughness is within a range of acceptable actual surface roughnesses, and storing a set of additive manufacturing parameters determined in a last iteration of steps a) to d); wherein predicting an actual resultant dimension based at least in part on the nominal parameter and the at least two second order variations comprises determining an expected effect of the at least two second order variations on the nominal parameter; and wherein determining an expected effect of the at least two second order variations on the nominal parameter comprises applying: probabilistic distributions of the at least two second order variations to the nominal parameter; mechanistic distributions of the at least two second order variations to the nominal parameter; and/or mathematically determined physics distributions of the at least two second order variations to the nominal parameter. probabilistic distributions of the at least two second order variations to the nominal parameter; mechanistic distributions of the at least two second order variations to the nominal parameter; and/or mathematically determined physics distributions of the at least two second order variations to the nominal parameter.