Agree it is very sensitive to the context. The outcomes are a mixed bag, but my biggest experienced failing was on a project starting naively with OBT and wait

Agree it is very sensitive to the context. The outcomes are a mixed bag, but my biggest experienced failing was on a project starting naively with OBT and waiting for things to become clearer, it did indeed soon became clear that we should have taken a more methodical approach, as we had the dual problem of huge dependencies and a very brittle data model! (I don't think there is an easy answer here btw, I am hoping for someone to describe a detailed and relatively generalisable playbook, hopefully soon!)