PTQ Q2 2026 Issue

Actual operation O-PAS is in use today in several locations. The largest and best-known deployment is ExxonMobil’s Lighthouse Project, which has been documented extensively in a vari- ety of sources. Briefly, it is the company’s resins finish - ing plant in Baton Rouge, Louisiana. It was built from the ground up using O-PAS-aligned equipment and software, and it operates with more than 30 controllers and 1,000 I/O points. The company has characterised this project as an example of how O-PAS technology can perform using an open, standards-based system, with all its hardware and software components sourced from various vendors and completely replaceable, interchangeable, and interopera- ble. Naturally, this has provided strong confirmation, along with extensive real-world experience and feedback, for O-PAS. The company also operates a smaller test bed for support, testing, and training purposes. ExxonMobil is not alone in this effort, with companies around the world also using this approach: • Shell has been operating an O-PAS testbed for more than two years. • Petronas has a testbed with 200 I/O, including analog inputs and soft I/O, at its INSTEP training facility in Batu Rakit, Terengganu, Malaysia. This has been operating since 2023 and it is being used to train a new generation of tech- nicians who will participate in larger deployments. • Reliance is operating an O-PAS testbed in cooperation with Yokogawa at its Jamnagar Refinery facility in Gujarat, India. Looking ahead ExxonMobil has been clear that its motivation to see the development of O-PAS has been cost and value-driven. It grew out of the challenge the company first faced 15 years ago when considering how much of its process auto- mation infrastructure across many facilities was reaching end-of-life. The thought of replacing conventional DCS architecture with all its dedicated hardware seemed hope- lessly antiquated, given the advances in computing power and standardisation, making it far easier and less costly to replace hardware with software. While there were oppor- tunities to add virtualisation to legacy DCS hardware, that was considered a partial solution at best, and ExxonMobil dismissed it as an option. So why must an old DCS be replaced? The obvious reason is hardware failure. Old systems, no matter how ruggedised, eventually quit working, and components that were common 20 or even 10 years ago are no longer available. Software is also an issue, since programs designed to run on those old systems are not easily transferred to more modern equip- ment. Hence, the desire was to replace dedicated hardware with an open system, moving from its proprietary tightly coupled software/hardware architecture and high costs. Moving to O-PAS practices may shift some of the tradi- tional service roles of the DCS provider to others, such as the end user, a system integrator, or an engineering firm. However, some firms, such as Yokogawa, are prepared to work in multiple O-PAS roles: as a product supplier, a system integrator, and a services provider. For example, Yokogawa developed its OpreX Open Automation SI Kit and an OPC

UA Management Package to significantly expand and strengthen its OPA system integration capabilities. These types of system integration services include extensive soft- ware development and hardware procurement, which are not dependent on any specific supplier, but are instead open to using best-of-breed software and hardware in each area. Consequently, an end-user company can design, sup- port, and upgrade or replace its own control system. That does not mean every installation has to be created from a blank page. The interoperability aspect of O-PAS applies to software as much as to hardware, and over time, com- panies will accumulate libraries of applications that can be copied from one site to another, hence the portability element. Well-developed security measures, using IT tech- niques, can be built in and fully integrated. Today’s DCS suppliers can participate as system integra- tors and software developers. The intellectual property built by those companies over many years of experience across multiple industries is still important and valuable. Yokogawa is taking this path, and this was our role with ExxonMobil and the Lighthouse Project: bringing know-how in control and optimisation strategies and its third-party component integration capabilities into the installed system. In the future, an end user/system integrator should be able to buy equipment from any O-PAS-certified supplier, or, when possible, even off-the-shelf components. The ultimate goal of an O-PAS-based control system is to be self-perpet- uating, with any element able to be replaced or upgraded as needed. All this said, O-PAS is not for everybody. Cost of ownership is a strong driver for O-PAS selection, and not all facilities or processes will be able to realise these savings. Other solutions may take a hybrid approach using some traditional elements supplemented by O-PAS-based capabilities. Yokogawa will continue to provide its Centum DCS, as will undoubtedly others in this space with their DCS products, retaining their long-established platforms. Participating in the process At present, there are more than 100 member organisa- tions in the OPAF of the Open Group. These include 20 global operating companies and many of the major DCS providers. Universities are beginning to participate as well. Naturally, end users are encouraged to join to drive the standard development effort and be a hands-on participant in designing the future. As participation grows and adop- tion and applications increase, the standard will become more fully defined, leading to more widespread use. The ultimate goal is to give end users the freedom and flexibility to use the approach that best fits their company, whether it is using a traditional DCS or an O-PAS system. Vien Nguyen is a Principal Software Architect at Yokogawa, leading the integration of emerging information technologies and industrial automation trends to enhance end-user value and global competitive- ness. He is an active member of the Open Process Automation Forum, co-chairs the OPAF Technical Working Group, and contributes to the development of the O-PAS standard. Nguyen holds Bachelor’s degrees in mathematics and aerospace engineering from the University of Texas at Arlington and a Master’s in space science from the University of Houston-Clear Lake.

PTQ Q2 2026