Managing the interworking between IT and OT

Now that the benefits and challenges of IT/OT convergence have been defined, it is critical to understand the basics of managing this convergence. A general framework for IT/OT projects is needed to harmonize the roles and divide the joint project or application into manageable elements or layers, as well as to align the elements with the business goals or drivers. The general IT/OT project approach is:

• Determine the business goals or drivers;
• Develop the implementation roadmap since IT/OT projects are likely multi-phase implementations;
• Develop the business and get stakeholder buy-in; and
• Develop the business process workflow and use cases

Once the business-process flow and use cases are well known, the detail elements—or tasks—of the project are defined. These include the data and interfaces for the various actors to interact. It is clear that OT owns the micro-vision and implementation of any solution, and IT owns the macro-vision and implementation of the same solution. OT groups work from the sensor to data collection to process control to transfer of data to a database.

Conceptually, OT works from the bottom upward, while IT groups work from the business process to data storage to data transport across dedicated networks or corporate networks. Conceptually, IT groups work from the top downward. Having a framework to align project interface, roles and functions is vitally important.

ISA-95 is a multilayer standard or framework that defines IT/OT convergence as five layers, with OT working layers 0 (sensing and manipulating process) to layer 3 (managing work flow)—or upward—and IT working layer 4 (managing business activities such as ERP or MRP) to layer 3 (establishing basic schedules)—or downward.

While the ISA 95 standards are not complete, the division and allocation of the overall IT/OT integration is a model that serves IT and OT groups as they define projects scope, divide applications or tasks, and define interfaces and communications.