[bumby]

What you bring up in terms of cascading failures is termed the "swiss cheese model"[1]

This is the traditional way to deal with system hazards. What has been talked about is the need for changing the way we think about software failures on safety critical systems, distinct from traditional failure mode approaches.

"The result is that software-related accidents involve a new type of accident, which can be called a component interaction accident: None of the components fail (all satisfy their specified requirements) but the problems arise from dysfunctional interactions among the components."[2]

[1] https://en.wikipedia.org/wiki/Swiss_cheese_model

[2] https://dspace.mit.edu/handle/1721.1/58930