<p>In this study, the painting process of detailed aircraft parts was optimized. A new model was proposed for optimizing the paint thickness of fixed-axis and route-oriented robots for a detailed part painting process within the scope of the aviation industry. The experimental methodology design was used to optimize the factor levels. The innovative surface paint thickness measurement approach was adapted in this study to reflect the aircraft paint thickness homogeneity requirements. The factorial design approach was then applied using the five independent factors, each of which has two levels. A regression equation was also obtained using ANOVA. Finally, using the desirability function approach, an optimization model was developed to set the optimal factor levels for obtaining the minimum paint thickness of the aircraft parts. The average value of the thickness obtained as a result is 17.6 microns, which was at the level of 25 microns. Thus, a very close result was obtained to the lower limit of the range specified in the design requirements (15 microns), and paint consumption decreased by approximately 29.6%. The proposed approach captures the thickness of the painted part.</p> Graphical Abstract <p></p>