I have approached this topic from the point of view of an airline, but the conclusions may be of value over a number of industries. In order to make the approach clear, it is worth defining some terms and also giving a simplified map of the subject.

I have referred in a number of places to “operational” engineering as opposed to “design and manufacture”; the term operational used in this sense should be understood to cover any activity based primarily on the use of machines to produce a service or material of some kind, rather than the design and creation of machines themselves. For example, transport as a whole would come in this category, as would the distribution of goods, the distribution of power in the form of electricity, and possibly mining operations and the production and distribution of crude petroleum.