Marketing-Open
Word only. No standard.
“Open” in the executive summary. No named standard, no version, no certification. A closed DCS with connectors bolted on.
Lock-inTotal
Free white paper · 12 pages · Insertion-ready RFQ clauses
“Open” now means four different things on a DCS quote.
Three of the largest names in process automation shipped announcements this quarter using the word open in the first paragraph. They mean four different things. Sort the paperwork before you sign, or lock your operation in for a decade.
- The Four Tiers of Open, expanded. Vendor plain-language definition, identification test, and 10-year buyer economics for each tier — Marketing-Open, OPC UA Connectivity, Software-Defined Proprietary, and O-PAS Conformant.
- Seven-dimension comparison matrix. Standard governance, third-party certification, data interoperability, application portability, multi-vendor mix, roadmap risk, and the RFQ language that qualifies each tier.
- Six specification clauses. Written for direct insertion into an RFQ, FEED spec, or master automation standard. Any bidder who can't answer them is telling you which tier they belong to.
- Appendix. The eight O-PAS profiles currently available for certification, the Part 1–9 standard map, and the primary sources behind every claim.
Referenced against The Open Group, OPC Foundation, Schneider Electric, Emerson, and Yokogawa primary sources.
Preview: the framework
Four tiers. One overloaded word.
Every DCS bid you read this year fits into one of these tiers. They don't carry the same lock-in profile. They can't be compared on price without first being sorted.
OPC UA Connectivity
Data portable. Logic not.
Legitimate multi-vendor data exchange via OPC UA. But OPC UA is not scoped to control-application portability. Your data moves. Your control strategy doesn't.
Lock-inControl layer
Software-Defined Proprietary
Hardware free. Runtime not.
Control logic decoupled from dedicated proprietary controllers. Runtime, orchestration, and application format still owned by the vendor. Real advance on hardware. Untouched on software.
Lock-inRuntime & roadmap
O-PAS Conformant
Third-party certified.
Certified against specific O-PAS profiles by an independent Recognised Verification Lab. Trademarked logo. Enforceable in a contract. Hardware from one supplier, applications from another.
Lock-inStandard-controlled
Why this matters right now
The definition of “open” is being decided this quarter.
Apr 16, 2026
First O-PAS OCF-001 certification. Yokogawa's OpreX Open Automation SI Kit becomes the first product independently certified conformant to O-PAS. Conformance clauses in an RFQ are now enforceable.
Jun 18, 2026
Schneider ships “the industry's first open, software-defined DCS.” Runs on the proprietary EcoStruxure Automation Expert runtime. The word open is now being redefined by vendors on their own terms.
Jun 25, 2026
ExxonMobil, Shell, and BP sat on the same ARC panel on AI-augmented HAZOP. One of five stated pillars: an interoperability foundation that “avoids vendor lock-in and reduces data silos.”
Jul 2026
Every major DCS incumbent now markets “open” or “software-defined” as a headline claim. Whoever writes the specification language first, on their next project, changes the negotiation for everyone who follows.
About the author
Trevor Cusworth
Consultant on open process automation and process safety intelligence. Works with CSI Automation on the O-PAS Fundamentals track for EPC engineering teams and owner-operator I&C leaders.
The white paper is a working document from ongoing procurement-spec advisory. Every claim is tied to a primary source cited in-line and listed in full in Appendix C.