Your choice! Mix and match if you like; you can put the regulatory control loops in the field if you wish, with advantages of performance and reliability. Complex control functions will stay in the DCS.
Supervisory functions, data analysis and links to management systems stay where they are now, but perhaps take extra data directly from field devices by pass-through via the DCS. The right level to put any function is the lowest at which all the necessary information is available. More.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.