In this short note, we provide some comments on the recent paper ''Improving the computing efficiency of HPC systems using a combination of proactive and preventive checkpointing'' by Bouguerra et al.. We start by identifying some errors in their equations. Then we explain that they do not actually use the distribution of lead times, contrary to statements by the authors. Finally, we show that their algorithm does not change policy at the best possible moment, and we point to our own work~\cite{rr-journal-prediction} for the (correct version of the) optimal algorithm.
