Networking is hardly a new technology, so why aren’t these OT systems taking advantage of it already?
There are many answers to that question, not least the long lives that many of these assets have, but certainly one of the reasons is concern about security. No corporate IT environment of any significant size can claim to have completely avoided all adverse effects from malware or external hackers. As the industry connects operational systems to the corporate network in an effort to improve visibility and enable some remote operational control (the two are not always easy to separate), no VP of Operations, Plant Manager, or CISO can fail to consider interruptions to these systems can have much more negative consequences than email going down.
Corporate networks already have considerable resources devoted to security in the form of personnel, software and hardware, but they are typically designed with a relatively hardened perimeter (Firewalls, IDS/IPS, etc.) around a relatively open internal network. Access to that internal network in well-designed environments requires strong authentication, but after a computer and an individual pass these checks they typically have relatively broad access. This design is probably near ideal to achieve the goals of corporate IT networks where the tradeoff between the value of sharing information and risking that information is different than in operational systems.
Companies do see substantial benefits from making operational systems visible to a group of personnel who have specialized expertise or similar roles in different facilities but don’t necessarily need to make the data – and certainly not operational access - widely available.