To optimize the selective laser sintering process in a laser metal sintering hybrid milling machine and to shorten development times, the process conditions were evaluated in terms of the power used in subsequent milling of the processed workpiece and studies were performed using parameter design and the Mahalanobis-Taguchi system. When the optimal conditions obtained from these studies were used as in-house standards, several problems emerged, including reproducibility of the gain. These problems were reexamined in several ways, including further experiments, for the purpose of establishing a method of using milling power to evaluate sintering conditions. Specifically, we reexamined the calculation of cut weight, noise factors, measuring methods, and evaluation methods. After the reexamination, another experiment was carried out and the results were studied.