MES, OT and the IIoT – what’s required for digitalisation?

May 2021 Editor's Choice  

My last opinion piece on the MES and OT saga turned out to be a good gauge of the perception of professionals in both realms. In the article, which appeared in the October 2020 issue of SA Instrumentation and Control magazine (, I asked whether OT will ever swallow up MES.

The response on LinkedIn and email was surprising. Some commentators vehemently defended the separation of the two, while others didn’t completely discount the possibility. We defined MES as applications that execute plant-related data in the business layer. 

We also defined OT as technology that is used in the process control layer. These are very simplistic definitions but will suffice for now, as that is another rabbit hole and there are many books written about the definitions and meanings of MES and OT.

The IIoT is what glues it all together 

Where does the IIoT fit in? Well, first let’s define it. The Industrial Internet of Things is the ability to connect devices (or things) to the Internet and to each other over various types of networks, using various types of protocols. The idea is that previously disadvantaged devices can now benefit from Internet exposure. Being connected allows these devices to share data with their owners and operators, which was previously impossible, or at least very difficult. Now apply that to an industrial environment and we open up a whole new world of possibilities (or a can of worms?) – namely, digitalisation.

Clear demarcations, for a reason

The world of OT exists for a reason. We cannot simply apply IT standards and processes to an industrial environment where we are focused on manufacturing processes that must run continuously without those pesky IT processes, standards and seemingly endless red tape, getting in the way. This is a popular misconception! For digitalisation to succeed the two domains have to integrate, they have to find that common ground where the goals of the enterprise become the shared objective. Securely allowing network traffic to flow as and when required, initiated by the OT domain data decision makers, is the thinking that has to be adopted before digital transformation can be achieved.

But how? 

Hand over the data decisions to the OT guys? Calm down IT professionals, there is a time and a place for everything. Digitalisation in its simplest form makes data available from where it is being created. MES systems, ERP systems, WMS systems and logistics systems are not the truest, rawest source from which data can be gathered. We want data from sensors, machines, PLCs, DCSs and HMIs etc. We want the data to be gathered from all stores, at any level and of any type. This is the value in the IIoT – the idea that we can get a window into the entire enterprise by having data connections to all relevant systems and data stores, not on an historical stack level, but on an holistic data-hub level. Traditionally, data would go from the sensor to the PLC (edge), HMI, scada and then to the MES in the business layer and from there onto the ERP and other business systems. The IIoT structure encompasses an extraction layer from any, and all, systems that aggregate and store data into the Unified Name Space (more on this in a future article). 

Visualisation is the window from which the information (worked and refined data) is visible to C-suite executives, buyers, planners, operators and engineers. This data is gathered from all relevant sources and then filtered, defined and refined for relevant eyes to make relevant decisions. The possibility exists for new information from existing assets to bring greater insights into existing processes. The IIoT architecture, protocols, software applications and partnerships (a hot topic right now in the world of 4IR) are how we will achieve digitalisation and the integration of OT and MES.

And why?

Well, because we need to unlock the benefits of 4IR through digitalisation. Having worked in a manufacturing IT environment for 12 years, I’ve been involved in the integration of MES and OT systems down into the plant networks, as well as up into the business layers. Based on those experiences, I believe that the IIoT is the vehicle that will allow us to achieve digitalisation to a level that unlocks the benefits of 4IR – a true transformation.