Why it matters now: control-system modernisation has stopped being treated as a maintenance line item and is now being written into ten-year demand models for industrial hardware. A cluster of market outlooks published on 28–29 August 2026 places modernisation of industrial automation systems — alongside semiconductor fab build-out and tightening safety-compliance regimes — at the centre of structural growth forecasts for process and motion components through 2035. For PLC vendors, distributors and system integrators, the read-through is significant: brownfield controller replacement, fieldbus-to-Ethernet migration and retrofit instrumentation are being modelled as a decade-long revenue stream, not a one-off upgrade wave.
The most explicit example is the low-pressure safety relief valve outlook published by IndexBox, which projects a 4.2% compound annual growth rate from 2026 to 2035 and attributes it to three converging forces: accelerating semiconductor fabrication capacity, modernisation of industrial automation systems, and stricter safety compliance across process industries.
Parallel outlooks for valve spool assemblies and vibration isolation mounting pads use the same logic, treating automation capital expenditure as a leading indicator for component demand. Both name automation majors — Schneider Electric, Honeywell, Yokogawa, Azbil, Festo, SMC, Norgren/IMI, Emerson’s ASCO and Eaton — among leading participants, a signal of how tightly valve, pneumatic and motion component demand is now coupled to controller and instrumentation refresh cycles.
Analyst Insight: The forecasting shift here is subtle but important. Analysts are no longer modelling valves, spools and isolation pads purely against plant output or oil-and-gas capex. They are modelling them against control architecture refresh cycles. When a controller is replaced, the surrounding pneumatics, positioners, relief devices and mounting hardware are frequently specified out at the same time — which converts a software-and-cabinet project into a multi-component procurement event.
Inside the numbers: what the 2026–2035 outlooks project
Read individually, each report is a niche component study. Read together, they describe a single demand engine: automation modernisation in the installed base, plus greenfield capacity in high-specification sectors.
Forecast snapshot: component and control-system markets to 2035
| Market |
Base value / index |
Forecast |
CAGR |
Source basis |
| Low-pressure safety relief valves |
Index 100 (2025) |
Index ~151 (2035) |
4.2% (2026–2035) |
IndexBox baseline scenario |
| Safety valves (broad) |
USD 4.6bn (2025) |
USD 7.5bn (2035) |
5.2% (2026–2035) |
Global Market Insights |
| Control valves |
USD 7.85bn (2025) |
USD 16.79bn (2035) |
7.90% (2026–2035) |
Market Research Future |
| Distributed control systems (DCS) |
USD 24.10bn (2025) |
USD 42.11bn (2035) |
5.74% (2026–2035) |
Market Research Future |
| Programmable logic controllers (PLC) |
USD 17.00bn (2025) |
USD 25.26bn (2034) |
4.47% (2026–2034) |
IMARC Group |
Figures are vendor-published projections drawn from separate methodologies and are not directly comparable. Treat them as directional indicators of momentum rather than authoritative revenue guidance.
One detail deserves attention: the DCS outlook identifies pharmaceuticals and life sciences as its fastest-growing vertical at a 7.62% CAGR, and cites refinery brownfield retrofits driven by tightening IEC 61511 functional-safety obligations. That is the same compliance pressure named in the relief-valve outlook, viewed from the controller side of the panel.
Why control-system modernisation is now a component-demand indicator
Modernisation projects rarely stop at the CPU. Replacing an obsolete controller typically triggers a chain of downstream decisions: new I/O architecture, revised safety functions, updated pneumatics and positioners, and additional sensing to feed condition-monitoring platforms.
That chain is why component analysts now watch automation budgets. A single line of capital expenditure on controller refresh propagates into valve, actuator and vibration-isolation demand across the same plant.
Market Trend: Compliance is the least discretionary of the three drivers. Semiconductor capex can be deferred and modernisation can be phased, but functional-safety and pressure-relief obligations carry audit deadlines. Where regulation sets the clock, demand becomes non-cyclical — and forecast confidence rises accordingly.
The four workstreams inside brownfield PLC modernisation
1. Replacing obsolete controllers
Discontinued platforms remain in daily service across heavy industry and process manufacturing, with Siemens S5 and early S7 estates a well-documented example. Migration paths are technically defined, but converting legacy logic to modern engineering environments remains a non-trivial engineering effort — and a persistent driver of spare-part and phased-replacement demand.
2. Migrating from legacy fieldbus to industrial Ethernet
Network data confirms the direction of travel. HMS Networks’ 2026 annual study of newly installed nodes puts industrial Ethernet at 79% share, up from 76% a year earlier and 34% when the series began.
Industrial network share of newly installed nodes, 2026 study
| Technology |
Share of new nodes |
Direction |
| Industrial Ethernet (all protocols) |
79% |
Up from 76% in 2025 |
| Wireless |
7% |
Steady |
| PROFIBUS |
4% |
Down from 5% |
| Modbus RTU |
3% |
Steady |
| CC-Link, DeviceNet, CAN/CANopen |
1–2% each |
Modest decline |
| Other fieldbus |
2% |
Down from 4% |
Source: HMS Networks annual industrial network market share analysis, 2026 edition. Shares reflect new node installations, not the total installed base — which remains substantially fieldbus.
3. Adding safety I/O and diagnostics
Tighter safety regimes push functional-safety logic out of hard-wired relay schemes and into certified safety controllers and safety I/O. Diagnostics coverage, not just shutdown capability, is increasingly what auditors ask about.
4. Instrumenting existing assets for predictive maintenance
Retrofit sensing on legacy machinery is the lowest-capital entry point to modernisation and often the first phase funded. It also explains why vibration isolation and condition-monitoring hardware appear in the same demand narrative as controllers.
High-specification first: semiconductors, batteries and pharmaceuticals
The outlooks reinforce an established pattern: the most demanding control architectures are specified first in new capacity, then filter into general manufacturing through retrofit programmes. High-availability controllers, precision motion and full batch traceability are being written into fab, gigafactory and pharmaceutical specifications as standard rather than optional.
The capital backdrop supports that claim. SEMI projects worldwide 300mm fab equipment spending rising 18% to USD 133 billion in 2026 and 14% to USD 151 billion in 2027, driven by AI chip demand and regional self-sufficiency programmes.
Semiconductor capital-spending context behind the component forecasts
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300mm fab equipment spending: +18% to USD 133bn in 2026; +14% to USD 151bn in 2027 (SEMI 300mm Fab Outlook).
-
Total semiconductor equipment sales: forecast to reach a record USD 156bn in 2027, a third consecutive growth year.
-
Wafer fab equipment: projected +23.1% to USD 143.9bn in 2026 after a record prior year.
-
Automation read-through: ultra-clean gas handling, high-purity valve trains, precision motion and cleanroom utility control — the highest-margin end of the component market.
Analyst Insight: Fab and battery projects set the specification ceiling; brownfield retrofits set the volume floor. Suppliers positioned only at the ceiling face lumpy, project-driven revenue. Those able to serve phased retrofit programmes — including legacy spares that keep an ageing line running until migration is funded — capture the steadier half of the curve.
Procurement implications for integrators and maintenance teams
If modernisation demand is structural rather than cyclical, sourcing strategy should reflect that. Three practical consequences follow from the 2026–2035 outlooks.
Plan dual-track inventory. Phased migrations require both current-generation controllers and discontinued spares to bridge the transition without unplanned downtime. Treating legacy parts as strategic inventory rather than dead stock is now a risk-management decision.
Specify the network before the CPU. With industrial Ethernet at 79% of new nodes, protocol strategy determines controller, I/O and gateway selection — not the other way round.
Bundle the compliance scope. Where safety I/O, relief devices and diagnostics fall under the same audit, sequencing them into one engineering package reduces validation effort and repeat downtime windows.
FAQ: reading multi-year automation forecasts
How reliable are these 2035 projections? They are vendor-published models, often indexed rather than absolute, and built on differing methodologies. Their value lies in the direction and the stated drivers, not in the decimal places.
Why do valve reports name automation companies as key players? Because pneumatic, motion and relief components are increasingly sold as part of control packages. Vendors such as Festo, SMC, Norgren/IMI, ASCO and Eaton sit at the intersection of fluid power and control, alongside system houses including Schneider Electric, Honeywell, Yokogawa and Azbil.
Does modernisation mean full rip-and-replace? Rarely. The prevailing model is panel-level hardware replacement — new controller, I/O and HMI — while preserving field wiring and instrumentation, with logic conversion as the main engineering risk.
Which sectors lead the modernisation spend? Semiconductors, batteries and pharmaceuticals set the specification standard; refining, chemicals, food and general manufacturing follow through staged retrofit budgets.
What is the biggest execution risk? Loss of legacy engineering knowledge. Programme conversion and commissioning depend on documentation and expertise that is retiring out of the workforce faster than it is being replaced.
The caveat that belongs in every forecast
Multi-year outlook reports are marketing instruments as well as analytical ones. The growth figures cited here are vendor projections published across late August 2026 and earlier in the year, and should be treated as directional signals rather than authoritative guidance.
What is harder to dispute is the structural argument. An ageing installed base, a measurable migration to Ethernet-based networks, non-negotiable safety obligations and a historic semiconductor investment cycle all point the same way — and they point to control-system modernisation remaining a durable demand driver well into the 2030s.
