Statistics are used all the time in safety critical designs. But, this is key, they are then balanced with the outcome expected due to each statistical failure.

Statistics are used all the time in safety critical designs. But, this is key, they are then balanced with the outcome expected due to each statistical failure. The more serious the outcome, the less the tolerated statistical failure. In the case of MCAS, from what we have read so far, it seems this analysis was biased toward a non-catastrophic outcome (e.g. manageable through pilot action). This may explain why the statistical failure of a single computer was deemed sufficient. Now, assessors have upped the stakes, and the stats do not work anymore. This indeed reveals a very serious problem in the RAMS process at Boeing, and exceed the scope of a « simple » software fix.