Industrie 4.0 Machine Upgrading

Many production companies still use industrial machines from installations that are several decades old.
These industrial systems will not be improved if they are not of their (mechanical) lifetime
but do not meet the current need for functionalities and energy efficiency within Industrie4.0
paradigm. By upgrading older industrial systems in a cost-effective way with sensors, actuators, controllers and computing power companies with those systems still realize this step. Dialogue teaches that the three most important of which companies are dying are:
(I) Finding a suitable approximation of the current state of the machine from instailation to the desired functional state, What are the quantifiable costs and benefits?
(it) Selection of suitable hardware and software that meets all requirements. Which technology from a multitude is needed for a specific machine?
(iii) Pathway guidance to connect the old with the new. How can companies implement concrete implementation?