that's done via Internet protocols instead of dedicated cable. The real first questions are:

What do you want monitored?

How much do you want monitored?

In the past I've had a little to do with setting up remote manufacturing machinery monitoring, but that was with direct cables and we had to know which of the instruments were worth such detailed monitoring. Experience has shown you do NOT need to monitor everything on everything all the time. Some are best with snapshots taken at different times, otherwise you get buried under way too much detail and fail to see the forest as a whole for the trees and the brush.

Another good point is how you want the information to be displayed, in some cases raw data as digits is good, while others are best shown as a line graph.

In short, you need to point out there's many hours of work needed to establish the relevant goals before you can even estimate how much it's going to cost to do, let alone any benefits.

One case I worked on years ago we had the per unit cost from another operation, so we could work out the cost of setting up remote monitoring for the two main productions lines was the equivalent of employing a person to do the relevant manual monitoring for ten years, heavy costs in safe installation of cabling as wireless gear was no good due to electromagnetic interference in the building. The current system had one person doing the manual monitoring of those two lines and three auxiliary lines that would still require the person to do, or more than double the costs to do the lot. Decision was made to leave it as manual.

This sort of analysis is where the consultants will be good, but they need clear goals before they can do any real estimates.