How often do highly complicated systems rely on some level of manual processes?
Or how about this: how often do highly evolved models (used for valuation or forecasting or decision support) incorporate highly subjective data?
In my experience, both of the above happen far more often than one might assume. I find this situation unsettles me. Our society derives much comfort from "systems", and yet very often the efficacy of a given system is highly sensitive to, potentially, one person's subjective input and/or one person's manual manipulation of relevant data.
On a somewhat related topic, how often does "success" in business or life come from non-intentional actions? Stories like the invention of Post-It Note glue being an accident that someone realized could be re-positioned as a new product in it's own right speak to this thought I'm having...