Abstract

This article explores the practical implementation of Geometric Dimensioning and Tolerancing (GD&T) according to the ISO GPS standards, focusing on the functional definition and consistent application of Datum Reference Frames (DRFs). DRFs, derived from a component’s functional geometry and assembly sequence, constrain six degrees of freedom to ensure stable alignment and reproducibility during production and assembly. The ISO GPS approach emphasizes a top-down consistency of DRFs across all product levels to prevent variation accumulation and quality issues. Tolerances—including position, profile, orientation, and form—are defined relative to DRFs based on product function, materials, manufacturing processes, and environmental factors.

Effective adoption of ISO GPS requires comprehensive training of designers, engineers, and quality personnel, supported by flexible courses such as computer-based training modules, as experienced in BOSCH. Integrating GD&T early in the design process enables systematic tolerance management, leading to optimized costs, enhanced product quality, and reliable manufacturing outcomes compliant with international standards.