Advanced process control. Includes MPC, complex cascades, real-time optimization. A layer above DCS.

Maintenance management software (SAP PM, Maximo, Coswin). Work order tracking, preventive plans, history.

Distributed control system for continuous, I/O-heavy processes. Redundant architecture, integrated engineering.

Enterprise management information system (SAP, Oracle, Microsoft Dynamics). Purdue level 5.

Operator interface — panel, screen or web. ISA-101 best practice: gray dominant, color reserved for abnormal.

Protection relay or intelligent electronic device in electrical substations. Target of IEC 61850.

Industrial Internet of Things: connected sensors, edge computing, cloud platforms, MQTT Sparkplug, OPC UA.

Manufacturing execution system between ERP and DCS/PLC. Traceability, scheduling, recipe management (ISA-95).

Predictive control based on a dynamic process model. Anticipates and optimizes over an N-step horizon.

Universal productivity KPI = Availability × Performance × Quality.

Classic feedback controller combining three terms (proportional, integral, derivative) for control loops.

Industrial automation controller with deterministic scan cycle and IEC 61131-3 languages (LD, FBD, ST, SFC). Core of discrete automation.

Remote telemetry and control unit using DNP3 or IEC 60870-5. Typical in wide-area SCADA networks.

Wide-area supervision and acquisition (water, energy, gas, rail). Remote RTU/PLC polling, historian, alarm management.

Two-wire Ethernet + power physical layer for ATEX zone 0/1. Natural successor of PROFIBUS PA / FF H1.

Low-cost binary bus for on/off sensors and actuators. Yellow flat vampire-tap cable, mixed power and signal.

Differential serial bus originally for automotive (Bosch 1986). Foundation of industrial CANopen and DeviceNet.

Dominant North American SCADA protocol for electricity and water. IEEE 1815. RTU-side time-stamping, event classes.

Ultra-fast Industrial Ethernet (Beckhoff/ETG). On-the-fly circulating frame, <100 µs latency. High-performance motion control.

Two-wire process bus (FieldComm) for ATEX zone 1 instrumentation. Direct competitor of PROFIBUS PA.

Protocol overlaying digital signal on the analog 4-20 mA loop. Sensor configuration without changing wiring.

Intelligent single-drop link between sensor/actuator and master. Power + measurement + diagnostic + parameterization on the same wires.

Grandfather of industrial protocols (Modicon, 1979). RTU (serial) and TCP (IP) variants. Universal and simple.

Ultra-light publish/subscribe protocol. Industrial Sparkplug B variant for IIoT cloud (auto-discovery, rich metadata).

IT/OT interoperability standard (IEC 62541). Rich information model, native security (Sign + Encrypt + X.509).

RS-485 serial bus. DP version (Decentralized Periphery) for distributed I/O, PA version for ATEX process instrumentation.

Deterministic Industrial Ethernet driven by Siemens / PI. Dominant in Europe. Classes: Standard, RT, IRT.

Set of Ethernet extensions (IEEE 802.1) making standard Ethernet deterministic. Convergence layer of future buses.

Burner management system — safe ignition sequence, flame supervision, fault shutdown. NFPA 85, EN 12952/12953.

Diagnostic Coverage. Fraction of dangerous failures detected by automatic internal diagnostics.

Emergency shutdown of a process. ESD system = SIS dedicated to rapid shutdown to safe state.

Failures per 10⁹ hours. Standard unit on component datasheets.

Systematic analysis of failure modes, their effects and their criticality. Risk analysis tool.

Systematic study of hazards and operability. Word-by-word analysis (More, Less, No, Reverse…) of deviations.

Hardware Fault Tolerance. HFT = 1: the function is preserved despite one failure (1oo2, 1oo2D, 2oo3 architectures).

Layer of Protection Analysis. Quantifies risk reduction by each IPL (Independent Protection Layer) to derive required SIL.

Management of Change. Formal process to track, assess and approve any safety-impacting change. IEC 61511 requirement.

Mean Time Between Failures. MTBF (h) = 10⁹ / FIT. Statistical — does not guarantee individual lifetime.

Mean Time To Repair. Directly affects PFD (shorter MTTR reduces simultaneous unavailability probability).

Probability of failure on demand (low-demand mode). SIL 2: 10⁻³ ≤ PFD < 10⁻². See also PFDavg.

PFD averaged over the proof-test interval T1. IEC 61508 reference metric in low-demand mode.

Probability of dangerous failure per hour (high-demand / continuous mode). SIL 2: 10⁻⁷ ≤ PFH < 10⁻⁶.

Risk Reduction Factor = 1 / PFD. How much the safety function divides the residual risk.

Safe Failure Fraction = (λSU + λSD + λDD) / λtot. Share of safe or detected failures.

Total response time of the safety function — sensor to actuator in safe state. Must be shorter than the process safety time.

Safety Instrumented Function — a specific safe-state action (e.g. burner trip on flame failure).

Safety Integrity Level (IEC 61508 / 61511). 4 levels: SIL 1 (lowest) to SIL 4 (most stringent).

Safety Instrumented System. Sensors + logic solver + final elements realising one or more SIFs.

Auto-ignition temperature. Temperature at which a mixture self-ignites without spark. Basis of T1-T6 classes.

European regulatory framework for explosive atmospheres. Directive 2014/34/EU (equipment) + 99/92/EC (workplaces).

Equipment Protection Level. Ma/Mb (mining), Ga/Gb/Gc (gas), Da/Db/Dc (dust). Determines permitted zone.

IEC international scheme. Mutual recognition of Ex certifications between test labs (ExTL) and certification bodies (ExCB).

Mechanical impact resistance rating. IK00 (none) to IK10 (20 J). Complements IP.

Ingress Protection rating. Two digits: 1st = solids (0-6), 2nd = liquids (0-9). E.g. IP65 = dust-tight + water jets.

Intrinsic safety (Ex i, IEC 60079-11). Energy in the circuit limited below ignition threshold even on fault.

Lower Explosive Limit. Minimum fuel concentration in air below which no explosion is possible.

Minimum Ignition Energy of a gas/air or dust/air mixture. Hydrogen: ~0.02 mJ; methane: ~0.28 mJ.

Upper Explosive Limit. Maximum concentration above which the mixture is too rich to explode.

French national cybersecurity authority. EBIOS RM framework, PASSI/PDIS qualifications, OIV oversight.

EU regulation on products with digital elements. Applicable end 2027. Security-by-design, 5 years of updates.

EU Regulation 2022/2554. Digital operational resilience for the financial sector. Applicable since Jan 2025.

Successor of antivirus. Endpoint agent, behavioural analysis, MITRE ATT&CK detection. CrowdStrike, SentinelOne, Microsoft Defender.

Official IEC 62443 term for industrial automation and control system as a whole.

Identity and Access Management. Okta, Microsoft Entra (formerly Azure AD), Ping. SSO, MFA, entitlement governance.

Industrial Control System — generic term covering PLC, DCS, SCADA. Near-synonym of IACS.

Intrusion detection system. In OT, passive sensors (Dragos, Nozomi, Claroty CTD) analysing ICS traffic.

Enterprise IT — workstations, servers, cloud, applications, data. Distinct from OT.

Multi-factor authentication: something I know + something I have + something I am. TOTP, FIDO2, badges.

Detection and response based on network traffic analysis (vs EDR on endpoints). Essential in OT.

EU Directive 2022/2555. Cybersecurity for essential and important entities. Transposed Oct 2024. Fines up to €10M or 2% turnover.

Operational Technology — PLCs, DCS, SCADA, sensors. As opposed to IT (information technology).

Privileged Access Management. Password vault + recorded sessions. CyberArk, Wallix, BeyondTrust, Thycotic.

Public Key Infrastructure. Generates, signs and manages X.509 certificates. Microsoft AD CS, HashiCorp Vault, EJBCA.

EU Regulation 2016/679. Personal data protection. Fines up to 4% of global turnover or €20M.

Security log collection and correlation. Splunk, Microsoft Sentinel, Elastic, Wazuh, Graylog.

Security orchestration and automated incident response. Palo Alto XSOAR, Splunk SOAR, Tines.

Security Operations Center. Human team + SIEM/SOAR/EDR tools running 24/7 to detect and respond.

Single Sign-On. One authentication grants access to multiple applications. SAML, OIDC, Kerberos.

Extended EDR aggregating endpoint + network + cloud + email for unified correlation.

Artificial intelligence. Includes machine learning, deep learning, generative AI, symbolic expert systems.

Deep Learning. ML based on multi-layer neural networks. Vision, NLP, audio.

EU Regulation 2024/1689. First worldwide AI regulatory framework. Risk-based (unacceptable / high / limited / minimal).

Generative AI. Capable of producing original content (text, code, image, diagram). Used industrially for PLC copilots.

General-Purpose AI. Category defined by the EU AI Act for models with broad capabilities (mainly LLMs). Specific obligations.

Large Language Model. GPT, Claude, Gemini, Mistral, Llama. Foundation of copilots and GenAI.

Machine Learning. Statistical models that learn from data rather than being explicitly programmed.

DevOps for ML. Model lifecycle: training, edge deployment, monitoring, drift detection, retraining.

NIST AI Risk Management Framework. 4 functions: Govern, Map, Measure, Manage. Published January 2023.

Natural Language Processing. Extraction, classification, text generation. Foundation of LLMs.

Open ML model exchange format. Lets you deploy a PyTorch/TensorFlow-trained model on any ONNX runtime (edge included).

Pattern combining an LLM with an indexed document base. Model queries the base before answering. Reduces hallucinations.

Cellular access point name. A private APN separates corporate mobile traffic from Internet — direct egress to group VPN.

Inter-domain routing protocol of the Internet. Exchanges routes between autonomous systems (AS).

Demilitarized Zone. Intermediate subnet between IT and OT. Purdue level 3.5: proxy, jump server, NDR sensors.

Label switching used by telco operators. SLA-guaranteed, stable latency. Expensive.

Network Address Translation. Lets multiple private hosts share a single public IP.

Software-defined WAN. Aggregates MPLS, Internet, 4G/5G with automatic failover. Cisco Viptela, Fortinet, Versa.

Reliable transport protocol of the Internet. Connection, ordering, retransmission. Base of OPC UA, Modbus TCP, HTTPS.

Connectionless Internet transport protocol. Lightweight, no delivery guarantee. Used by DNS, SNMP, optional MQTT.

Virtual LAN. Logical segmentation on a switch (IEEE 802.1Q). Does NOT replace a firewall for security.

Encrypted tunnel between two networks or user and network. IPsec, OpenVPN, WireGuard, SSL VPN.

Zero Trust Network Access. VPN successor — continuous verification of every access, regardless of perimeter.

Basic Process Control System (vs SIS). Standard DCS or PLC. IEC 61511 §3.2.13.

Factory Acceptance Test. System testing at the manufacturer before delivery. Paired with on-site SAT.

Piping and Instrumentation Diagram. Shows equipment, lines, instruments, valves. ISO 10628, ISA-5.1.

Process Flow Diagram. Simplified diagram showing major equipment and flows. NOT to be confused with safety PFD.

Process Hazard Analysis. Includes HAZOP, what-if, LOPA. Regulatory requirement (OSHA PSM, Seveso).

Pressure Relief Valve (progressive opening). Often used interchangeably with PSV.

Pressure Safety Valve (pop-action). Overpressure protection. ASME VIII, EN ISO 4126.

Site Acceptance Test. Final verification after installation and connection, before commissioning.

CE marking. Conformity with European directives for market placement. Self-declaration by manufacturer.

Disaster Recovery Plan. Technical procedures to restore service after major incident. Complements the BCP.

Good Laboratory Practice. OECD framework for regulated laboratory studies.

Good Manufacturing Practice. Mandatory pharma framework (EU GMP, US FDA 21 CFR Part 211, 21 CFR Part 11 on electronic records).

Key Performance Indicator. Quantitative measure for steering and evaluation.

Minimum Viable Product. Simplest version already delivering value, to be enriched later.

Original Equipment Manufacturer. Designer and builder of an equipment, vs integrators or resellers.

Proof of concept. Small-scale prototype demonstrating that a technical idea works, before full deployment.

Backtest on historical data. Before a live POC, validation on 12-24 months of past data.

Service Level Agreement. Contractual commitment on service quality (availability, response time).

Post-Brexit marking for the UK market (England, Wales, Scotland). Coexists with CE for Northern Ireland.

Carbon Border Adjustment Mechanism. Reporting since Oct 2023, payment from 2026. Steel, aluminium, cement, fertilizers, H₂, electricity.

Carbon capture, utilization and storage. Post-combustion, oxy-fuel, geological sequestration, valorization (e-fuels, carbonation).

French white certificates scheme. Obligation on energy suppliers. Funds 10-80% of eligible energy efficiency projects.

EU Directive 2022/2464. Mandatory sustainability reporting for ~50,000 EU companies from 2024.

EU Directive 2023/1791 (recast). EU target 11.7% energy consumption reduction by 2030. Mandatory audit for large companies.

Energy Performance Indicator. Normalized metric for energy efficiency monitoring (ISO 50006). E.g. kWh/tonne produced.

Environmental, Social and Governance criteria used by investors for sustainability assessment.

European Sustainability Reporting Standards. 12 standards adopted by Delegated Regulation 2023/2772 under CSRD.

EU Emissions Trading System. CO₂ market for installations >20 MW thermal. Current price ~€80/tCO₂.

International carbon accounting framework. Defines scopes 1, 2, 3 used worldwide for GHG reporting.

Long-term Power Purchase Agreement (10-20 yr) with a renewable producer. Locks price and guarantees of origin.

Voluntary initiative validating that corporate emission reduction trajectories are +1.5 °C-aligned. SDA methodology.

Capital expenditure: money spent once to acquire a durable asset (machines, controllers, construction). Depreciated over its life.

Levelized cost of energy: average cost of an MWh over a plant's whole life (CAPEX + OPEX). Compares solar, wind, gas, nuclear on one basis.

Operational expenditure: money spent continuously to run an asset (energy, maintenance, staff, consumables). Recurring.

Return on investment: gain relative to the outlay, as a percentage. With payback time, it judges a project's profitability.

Total cost of ownership across the full life cycle: purchase, operation, maintenance, end of life. The real basis to compare two solutions.

Total expenditure = CAPEX + OPEX. A neutral view between buying and operating, used notably in regulated network industries.