We address accurate computation of on-orbit upset rates in advanced technologies, with a focus on FD-SOI at the 28 nm node. Heavy-ion measurements performed on FD-SOI SRAM bit-cells give experimental evidence of the technology’s intrinsic robustness in space environments; this extreme reduction of sensitive volume dimensions deeply affects the assumptions pertaining to the radiation response models used to predict upset rates. The generic “Integral Rectangular ParallelePiped” (IRPP) model, although requiring careful setting of its parameters, provides us with first-order estimates of the error rate. We then present a custom FD-SOI response model within our Monte-Carlo simulation chain, enabling comparison with IRPP and further analyses.