At a guess I&#x27;d say that the probability of a fault in a piece of software <i>does</i> approximately match the cost of it failing. A phone game is very likely to have more bugs than a banking system. My point is that both applications actually work really well. In my experience premium phones games crash maybe once in every thousand runs. Bank money transfer software crashes perhaps once in every few billion runs (that&#x27;s a total guess but we&#x27;d hear about it if it was higher and there are a lot of bank transfers every day). I think that&#x27;s quite good.