Fused Filament Fabrication (FDM) has emerged as a prominent and innovative manufacturing technique, facilitating the creation of intricate, lightweight components at reduced time and cost. Despite its advantages, the productivity and mechanical performance of 3D-printed parts remain challenging areas. Hence, there is a growing interest in investigating the interplay between FDM build time and mechanical properties. Structural parameters such as layer thickness (Lt), raster angle (Ia), and air gap distance (Ifd) can exhibit conflicting effects on productivity and mechanical properties. This study employs GRA and VIKOR techniques for the multi-criteria selection of 3D printing, aiming to optimize both printing time and specific flexural properties of PLA/copper composite beams constructed in the edge direction. We compare the parameters selected by both methods and evaluate their impact on the responses. The behaviors of the two models differ: GRA optimizes two responses the specific stiffness ans specific strength, while VIKOR is more effective for minimising printing time. Both models select the lower raster angle of 0° as optimuim. Lt significantly influences printing time, being the primary parameter in the VIKOR method, whereas Ifd primarily contributes to mechanical properties.