Imperial vs Metric - When Does It Matter?

Imperial vs Metric - When Does It Matter?
The world communities are very much individuals when it comes to standardising how to describe "things" like weight, length, value..... etc.These "things" exist in our world but there is no single definition for most "things", if not all, that can be used universally. The majority are used by custom acceptance in the social environment in which they were created and are put to use..
Of interest to our industry is that almost of our requirements to define a "thing" that we want to "use" is confined either of two systems - "imperial" and "metric" based "things" and with perfect interchangeability. .