We applied the model to characterize the observed trends in detail, revealing that thermal spikes occur due to the release of latent heat induced by nucleation events both in the monitored vials and in their neighborhood. The emergence of a stationary phase was explained by the interplay between both the heat generated by ice formation, governed by nucleation, and the heat removed via external cooling. The model also confirmed the position-dependency of the thermal evolution, where vials freeze in average later the closer they are to the core of the pallet. In addition, it revealed a yet unknown, but potentially relevant batch heterogeneity among vials in equivalent positions that could not be inferred from the thermal monitoring; this variability results from the interplay of stochastic nucleation and thermal interaction among vials. Since it may affect the stability of the frozen drug product, it should be considered in drug development and in freezing process design: the model provides information on the variability in the nucleation and solidification behavior among vials, and thus may inform the stability analysis to ensure that quality requirements are met for the entire range of predicted values.