Presentation on the complementary roles of Anthropomorphic Test Devices (ATDs) and Human Body Models (HBMs) in frontal impact assessment. ATDs provide standardized physical evidence at defined reference conditions based on fixed anthropometries, while HBMs can represent population variability through morphable anthropometry. HBMs extend assessment to human and crash variability that standardized ATD tests cannot practically cover, including occupant size variants, seat positions, postures, and crash severities. Neither tool is a universal substitute for the other; complementary capabilities improve robustness and confidence in real-world occupant protection performance.