PT Journal AU Vendittoli, V Polini, W Josef, W Moroni, G TI A Synthetic Geometric Performance Index for Parts Manufactured by VAT Photopolymerization SO Manufacturing Technology Journal PY 2025 BP 244 EP 251 VL 25 IS 2 DI 10.21062/mft.2025.028 DE Additive Manufacturing; Geometric Product Specifications; VAT photopolymerization; Biodegradable resin; Performance Index AB Geometric deviations play a crucial role in the quality of additive manufacturing, particularly in parts made with biodegradable resins. Accurately controlling dimensional and geometric variations in manufactured components is critical for achieving defect-free production and meeting functional standards. However, defining a final quality score can be challenging due to numerous dimensional and geometric deviations associated with a part. An innovative metric for evaluating geometric performance was created to measure dimensional precision in components produced through VAT photopolymerization. The index measures the dimensional and geometrical deviations, revealing that external surfaces exhibit greater precision than internal ones. This difference is likely due to internal surfaces overcoming heat dissipation challenges during the cooling process, resulting in less shrinkage for external surfaces. This index is essential in various stages of the manufacturing process, including part design, design for manufacturing and assembly, quality assurance, and process planning, helping to select the appropriate additive manufacturing technology and optimal process parameters. ER