Abstract The objective of this paper is to develop a Taguchi
optimization method for low surface roughness in terms of pro-
cess parameters when milling the mold surfaces of 7075-T6
aluminum material. Considering the process parameters of feed,
cutting speed, axial-radial depth of cut, and machining tolerance,
a series of milling experiments were performed to measure the
roughness data. A regression analysis was applied to determine
the fitness of data used in the Taguchi optimization method using
milling experiments based on a full factorial design. Taguchi
orthogonal arrays, signal-to-noise (S/N) ratio, and analysis of
variance (ANOVA) are used to find the optimal levels and the
effect of the process parameters on surface roughness. A confir-
mation experiment with the optimal levels of process parameters
was carried out in order to demonstrate the effectiveness of the
Taguchi method. It can be concluded that Taguchi method is very
suitable in solving the surface quality problem of mold surfaces.