Choosing a Future-Ready HMI

Summary

Choosing a durable product or service requires a degree of commitment, often in terms of years, or even decades in the case of industrial automation. While specifiers need to consider what design elements yield the most cost-effective minimum viable product, they are rightfully concerned about being locked-into something that will constrain normal upgrade efforts, and/or require a costly and risky rip-and-replace project in the future. Sometimes a simple commodity product is the right tactical choice, but increasingly there is a need to select a more strategic product able to support cloud connectivity, advanced features, upgrade paths, and scalability.
 
While not every industrial machine, production line, or plant has a human-machine interface (HMI) associated with the automation system, many do because this is the most effective way for the labor force to interact with its equipment. The HMI is often located right on a machine or in a nearby control room. A pipeline or water system with widely distributed operating assets would more likely use a supervisory control and data acquisition (SCADA) system, with the main interface located in a control center.
 
But even the smallest original equipment manufacturer (OEM), an end user performing a basic project, or a systems integrator (SI) supporting these groups will find it beneficial to plan ahead. End users installing equipment may think “what if my HMIs need to grow into a SCADA?” An OEM may be selling a modest machine today, but what if their customer wants to closely integrate it into the plant, or what if the OEM can connect with a fleet of these machines and offer extended diagnostics, analytics, and services to their end user? These and many other applications require a future-ready HMI (Figure 1).

• automation platforms of all types, from programmable logic controllers (PLCs) to industrial PCs, and everything in between
• a multitude of intelligent industrial internet of things (IIoT) devices at the operational technology (OT) edge, and
• useful information technology (IT) resources such as weather, enterprise resource planning, and other databases.

 
Beyond ordinary HMI

A look at the origins and evolution of HMI/SCADA provides some insights as to why designers and specifiers should factor the future into their decisions. One way to characterize significant HMI/SCADA development is the following general progress and associated technology inflection points:

• Basic HMIs (1990s): As Microsoft Windows became suitable for industrial applications, and the creation of I/O servers enabled connectivity to almost anything, PC-based HMI combined with more capable PLCs replaced specialized distributed control systems (DCSes) in many new applications.
• SCADA (2000s): The rise of IT throughout OT—especially effective Ethernet networking and more widespread standardization—supported user needs for greater distributed functionality, and for extensive historian and reporting functions.
• IIoT Integration (2010s): The proliferation of IIoT—based on web technologies, and protocols such as MQTT and OPC UA—combined with lightweight and intelligent devices, greatly expanded the multitude of data sources HMI/SCADA could and should access, and expanded the platforms where visualization and computing could be performed.
• Cloud Architecture (2020s): More thorough integration with the cloud—especially for providing advanced machine learning (ML) and artificial intelligence (AI) analytics—and a move towards a unified namespace, combined with great architectural freedom now support OT/IT convergence and mobility, providing new user experiences such as the “citizen-developer.”

In summary, HMI/SCADA started at the edge, evolved to incorporate supervisory and operations center functions, and has continued adapting to perform other roles, some of which were unanticipated. The next HMI/SCADA developments will include generative AI (Gen-AI) technologies to increase development-time work efficiency, while delivering easier run-time insight generation.
 
It is now clear how progress in computing power, networking, and communication protocols over the years have rapidly enhanced the capabilities of HMI/SCADA from a basic localized experience to something far richer and more distributed. Each technology inflection created or enabled new end user behaviors, but each has required new user investments in training and products, and sometimes wholesale changeouts.
 

Accessing advanced HMI/SCADA

There remains a great need for basic HMI functionality, which has become a bit commoditized. But the trend of accelerating HMI advances, especially over the past 15 years, is pushing specifiers to reconsider their technology selections. There is now a greater emphasis on total lifecycle costs, design longevity, and potential new efficiencies and revenue streams, as opposed to meeting minimum requirements. Users and specifiers are looking for a better way to navigate through improving HMI/SCADA technologies, instead of being forced to research a multitude of products and features in an attempt to assemble a cohesive solution.
 
A truly modern HMI/SCADA platform addresses these concerns by offering the broadest range of connectivity and capabilities, standardization for configurations, user-defined types (UDTs) for data, flexible development/licensing options, guaranteed upgrade paths, and multiplatform deployment and containerization.

HMI/SCADA unlimited

HMI/SCADA is bound to physical assets which endure for decades. Implementers need the ability to cost-effectively configure just what is essential for a given project—for a machine, a production line, a plant, or across an enterprise—so they can safely and efficiently operate their assets. Yet they are increasingly aware of the long-term value of scalability for themselves and their customers, as compared to the short-term illusory value of a constrained choice.
 
There is some attraction to choosing a variety of mix-and-match and supposedly best-fit products and options to build out a solution. However, experienced implementers know the cost, complexity, and risk associated with evaluating, testing, procuring, and supporting too many products. This approach sometimes takes them down the path of a technological dead-end, or it might be more susceptible to growing cyber threats, among other problems.
 
To address these and other issues, specifiers and implementors are often best served by selecting a comprehensive HMI/SCADA platform, provided by a supplier with decades of industry experience (Figure 3). A supplier of sufficient size and scope, and with a proven record of preserving customer deployment configurations even as technology advances, is uniquely positioned to help users access all the technologies they need, initially and into the future. An experienced HMI/SCADA supplier will constantly implement improving technologies, while insulating users from the complexity of implementing these advances.
 
 

Flexibility is value

While industrial automation technologies commonly lag other commercial technologies, they clearly evolve and improve. For organizations using industrial automation technologies, if they are not evolving as well then it is likely they are losing ground. Buying something limited may be expedient, but it rarely supports evolution.
 
When it comes to selecting an HMI/SCADA platform, the choice between cost-effective and capable need not be exclusive. It can be tempting to choose the most basic route, but the amount and variety of data, visualization needs, and analytics possibilities is increasing every day. For end users, OEMs, or SIs selecting HMI/SCADA for applications large or small, the best strategy is to select a platform which easily and cost-effectively meets their basic needs, while demonstrating a proven record of future-proofing.
 
_{In-text images and author headshot courtesy of AVEVA.}