Integration and AI Glossary

39 of 39 terms

PLCProgrammable logic controllerPlant and equipment

The industrial computer that runs a machine or a process. It is rugged, behaves predictably and is designed to do the same task reliably for twenty years.

What it means for your budget: The controller's age decides your options. A controller from the last ten years usually supports an open protocol, and connecting it takes days. One from the 1990s may need a gateway or a licensed driver, or you may need to read its data through the machine's SCADA system instead.

SCADASupervisory control and data acquisitionPlant and equipment

The software layer above the controllers. Operators use its screens, alarms and trend charts to monitor and control the plant.

What it means for your budget: SCADA is often the cheapest source of data, because it is already connected to every controller. Reading data from SCADA, instead of from thirty separate controllers, can remove most of the integration cost.

HMIHuman-machine interfacePlant and equipment

The screen on or beside a machine. It works like SCADA, but for one machine only.

What it means for your budget: If a machine has an HMI and no other data connection, a camera that reads the screen is a practical way to get the data. It is often cheaper than the alternatives.

HistorianPlant and equipment

A database built for time-series plant data, storing values with timestamps and quality flags at high volume for years.

What it means for your budget: If you have a historian, you already have the operating history that analytics needs. If you do not, plan for a year of data collection before any model can learn from patterns.

MESManufacturing execution systemPlant and equipment

The system between the business software and the plant. It decides what to make, in what order and on which line, and records what was actually made.

What it means for your budget: Vendors often sell an MES to small and mid-sized firms that only needed three integrations. A full MES implementation is long and expensive. Limit the scope strictly to the tasks you cannot do today.

OTOperational technologyPlant and equipment

All equipment that controls the physical process, such as controllers, sensors, drives and safety systems. IT, by contrast, handles information.

What it means for your budget: The difference decides who does the work. OT work needs engineers who will not stop a production line to install a software patch. That skill is priced differently from IT support.

FieldbusPlant and equipment

A digital network that connects controllers to field devices. Examples are PROFIBUS, Modbus RTU, CANopen and DeviceNet. Most are serial networks that are older than industrial Ethernet.

What it means for your budget: A fieldbus needs a gateway, and choosing a gateway needs a site survey. Both are cheap. Find out about any fieldbus before you sign a fixed-price quote.

4–20 mA loopPlant and equipment

The analogue signal standard for process instruments. It uses current instead of voltage, so cable resistance does not affect the reading. The signal starts at 4 mA instead of 0, so a broken wire reads differently from a zero value.

What it means for your budget: A low-cost module can read the loop alongside the existing system, which makes this one of the cheapest retrofit options. Each loop carries one value, so a machine with twelve values to measure needs twelve loops.

Dry contactVolt-free contactPlant and equipment

A relay output that opens or closes a circuit to signal a state, such as running, stopped, faulted or cycle complete.

What it means for your budget: This is the cheapest data on any machine, and the most often overlooked. Counts and run times from dry contacts answer many of the questions that firms pay for much larger projects to answer.

P-F intervalPlant and equipment

The time between the point when a failure becomes detectable and the point when the equipment fails. This number decides whether condition monitoring is worth paying for.

What it means for your budget: If the interval is months, monitoring gives you time to plan a repair. If it is hours, monitoring gives you an alarm you cannot act on, and a spare part is a better use of the money. Our predictive maintenance screener tests this.

Purdue modelPlant and equipment

The reference architecture that layers a plant from field devices at Level 0 to the enterprise at Level 4, with an industrial DMZ between plant and business at Level 3.5.

What it means for your budget: This model has practical consequences. Security reviews use its terms, and its levels decide where the firewalls go and where the money is spent.

IP ratingIngress protectionPlant and equipment

A two-digit rating. The first digit covers protection against solids; the second covers water. IP66 is dust-tight and resists powerful water jets. IP69K also resists high-pressure hot water.

What it means for your budget: If you specify too low a rating, the device may fail within eight months. If you specify too high a rating, you pay more for cooling and the device is harder to access. In a tropical climate, condensation is a greater risk outdoors than rain.

Industrial DMZIDMZ, Level 3.5Networks and security

A separate network zone between the plant network and the business network. Data passes through this zone, so no traffic crosses directly between the two networks in either direction.

What it means for your budget: On a small or mid-sized site, this is often one secured server and a set of firewall rules. No other single change resolves as many findings in a segmentation review.

SegmentationNetworks and security

Dividing a network into zones so that a problem in one zone does not spread to the others. In a plant, this mainly means keeping the control network separate from the business network.

What it means for your budget: Segmentation costs far less before an integration than during one. During the project, it becomes a change request against a signed scope. After the project, the usual trigger is a security incident.

Air gapNetworks and security

The claim that a network has no connection to any other network. In practice, this claim is almost always untrue.

What it means for your budget: Test the claim before you rely on it. We find the same three connections on nearly every site: USB sticks, the vendor's cellular router and engineers' laptops.

Jump hostBastion, remote access brokerNetworks and security

A controlled server that vendors and engineers must connect through, so they have no direct path to the equipment. Each session is opened on request, recorded and then closed.

What it means for your budget: The cost is modest, and it replaces permanent VPN accounts. It also keeps a record of every access, which is the first thing an auditor or insurer asks for.

Data diodeNetworks and security

Hardware that physically allows data to travel in one direction only: out of a protected network.

What it means for your budget: A data diode is expensive and cannot be bypassed. It is justified where a regulator or a safety case requires it. Elsewhere it is usually more than the site needs, and a firewall whose rules have a named owner gives proportionate protection.

Edge deviceEdge gatewayNetworks and security

A small computer installed near the equipment. It collects data, stores it temporarily and forwards it. It keeps working when the network connection is down.

What it means for your budget: Most modern integrations use edge devices. The most important feature is temporary storage (buffering), because it lets a site with an unreliable connection work without losing data.

RPARobotic process automationAI and automation

Software that operates existing applications the way a person would, by clicking, typing and copying between screens.

What it means for your budget: RPA is fast to build but breaks easily, because it depends on screens staying the same. Use it where no API (application programming interface) exists and the process is stable. Do not use it as a permanent replacement for proper integration.

Agentic workflowAI and automation

An automation where a language model decides the sequence of steps as it goes, calling tools along the way.

What it means for your budget: Agentic workflows are useful where each case is different, but they are harder to test than fixed rules. Budget for supervision and an audit trail as well as the build.

Computer visionAI and automation

Software that extracts information from images. Examples are reading a gauge, counting units, checking a label, finding a defect and reading a container number.

What it means for your budget: The camera is the cheap part. Most of the work and cost is in the lighting, the mounting and the handling of cases the system reads wrongly.

Predictive maintenancePdM, condition monitoringAI and automation

Measuring the condition of equipment to predict a failure before it happens. It works only where wear can be measured and there is time to act on the warning.

What it means for your budget: Vendors often sell it for problems it cannot solve. Random electronic failures give no warning to detect. For parts that wear out with use, counting cycles is cheaper and more reliable. Ask which failure mode it targets before anyone quotes.

Digital twinAI and automation

A live model of a physical asset or process, updated from real data, used to simulate or predict.

What it means for your budget: Vendors overstate this term more than any other in this glossary. A dashboard is not a digital twin. A real twin is expensive and needs a validated model. It is justified only for high-value continuous processes. A packing line does not need one.

Model driftAI and automation

The gradual fall in a model's accuracy as real conditions move away from the data it was trained on.

What it means for your budget: Drift is why an AI system needs an operating budget as well as a build budget. A monitoring process must detect the decline, and a named person must be responsible for retraining the model.

Human in the loopAI and automation

A design where a person reviews or approves the automation's output before it takes effect.

What it means for your budget: Human review reduces risk, but it also reduces the saving. The business case must include both effects. An automation that is 90% accurate with review is often worth more than one that is 95% accurate without it.

Exception pathAI and automation

The process for cases the automation cannot handle. Every automation has one, whether or not anyone designed it.

What it means for your budget: This is where automation business cases usually fail. If 20% of cases go to the exception path and nobody planned for them, staff still do much of the promised saving by hand.

Retrieval-augmented generationRAGAI and automation

Giving a language model access to your own documents when it answers a question, without training the model on them.

What it means for your budget: RAG is the usual approach for questions about your manuals, procedures or records. It is cheaper and easier to control than fine-tuning. Each answer can be traced to a source document, so you can check and defend it.

Discovery phasePaid discovery, survey phaseCommercial

A short paid engagement that records what is actually installed on site. It produces the specification that the build is quoted from.

What it means for your budget: This is the best-value spending on an integration project. It costs a fraction of the build, and without it a fixed price has little meaning.

As-built documentationCommercial

Drawings and schedules that show what was actually installed, which may differ from what was designed.

What it means for your budget: Missing as-built documents add cost to every project. Someone must survey the site to recreate them, either before the quote or during the build. The survey costs much less before the quote.

Tag listPoint list, I/O scheduleCommercial

The itemised list of every value to be read or written, with its address, type, units and range.

What it means for your budget: This is the most useful document you can prepare before you ask vendors to quote. Without it, a vendor's quote is a guess, but the variation charges that follow will be real.

Vendor lock-inCommercial

Being unable to change supplier without replacing the system, because the supplier owns the data, the interfaces or the licences.

What it means for your budget: You usually pay for lock-in around the fifth year. Ask what happens to your data if you leave, and have the answer written into the contract.

Total cost of ownershipTCOCommercial

The full cost of a system over its life: the build, plus licences, support, hosting and the staff hours spent on it each month.

What it means for your budget: Running costs are typically 15% to 22% of the build cost each year. A business case that leaves them out is incomplete.

HandoverCommercial

The point when you take over the running of the system. You should receive the documentation, credentials and source code, and have a trained person to use them.

What it means for your budget: Agree what handover includes before you sign. Clients often find out too late that they do not have the source code, the credentials or the right to hire another integrator.

ISO/IEC 42001Assurance and compliance

The management system standard for artificial intelligence, published in 2023. Organisations can be certified against it. It follows the structure of ISO 27001 and adds requirements specific to AI.

What it means for your budget: More tenders now ask for it. Its main new requirement is the AI system impact assessment, which covers the effect of the system on the people it affects. ISO 27001 has no equivalent, so this is where most organisations find their gap.

Statement of ApplicabilitySoAAssurance and compliance

The document that records which controls in the standard apply, which are in place and why any are excluded.

What it means for your budget: Auditors ask for it early. Writing it accurately takes about a week. Recreating it during an audit takes much more effort.

NonconformityMajor, minor, findingAssurance and compliance

A failure to meet a requirement, recorded by the auditor. A major nonconformity stops certification. A minor one delays it.

What it means for your budget: This difference is why a gap analysis before the audit is worth doing. Major nonconformities are most common in three areas: leadership, risk assessment and evidence that the system is in use.

TraceabilityAssurance and compliance

The ability to show afterwards what a system did and why. This covers its inputs, its decisions, the software versions and who changed what.

What it means for your budget: Traceability is cheap to include in the design and expensive to add later. If a regulator, a certification body or a customer audit is involved, treat it as a requirement.

ValidationAssurance and compliance

Proving, with evidence and under a defined test protocol, that a system does what it is required to do.

What it means for your budget: Where validation applies, it typically takes a fifth of the project effort. It applies more often than clients expect when a certification body or a classification society is involved.

Functional safetySIL, IEC 61508, IEC 61511Assurance and compliance

The engineering discipline for systems whose failure could injure someone, such as interlocks, emergency stops and protective functions.

What it means for your budget: Safety work is a separate project, with its own review process and competence requirements. If an integration affects a safety function, an independent review is mandatory and its schedule cannot be shortened.