ISO 22400 is the international standard that defines how manufacturing key performance indicators (KPIs) are named, calculated, and structured, so that every shift, plant, and software system measures performance the same way. It tells you what each metric means. It does not tell you which KPIs to chase or what targets to set. That part stays with you.

If your shop already tracks OEE, availability, or scrap rate in spreadsheets that nobody fully trusts, ISO 22400 is the rulebook that settles the "whose formula is right?" debate. This guide covers what the standard actually defines, the KPIs that matter most for discrete and job shops, and how to turn a definition on paper into a live number your team acts on.

What is ISO 22400?

ISO 22400, formally titled Automation systems and integration. Key performance indicators (KPIs) for manufacturing operations management, is an industry neutral framework for defining and exchanging manufacturing KPIs. It applies to batch, continuous, and discrete production alike.

The standard lives inside the broader IEC 62264 hierarchy and places its KPIs at Level 3, manufacturing operations management (MOM). That is the layer where production, quality, inventory, and maintenance are executed and monitored, sitting between the ERP layer above and the machine controls below. The KPIs are meant to be calculated from real control system data, not estimated by hand at the end of a shift.

It comes in two main parts:

• ISO 22400-1 covers the overview, concepts, and terminology. It was reviewed and confirmed current in 2025.
• ISO 22400-2 is the working part. It defines the formulas for roughly 34 KPIs, describing each one by its formula, time behaviour, unit, intended user (operator, supervisor, or manager), and use case. A revision is currently in progress.

The point of all that precision is comparison you can trust. When two shifts, two plants, or you and your customer all use the ISO definition of "availability," the number finally means the same thing to everyone.

What ISO 22400 does not do

Knowing the limits matters as much as knowing the contents:

• It does not prescribe which KPIs your operation should use.
• It does not set targets or define what counts as a "good" score.
• It does not tell you how to run a continuous improvement program.

So the often quoted "world class OEE of 85%" is not part of the standard. It is an industry rule of thumb. Set your own targets by asset, shift, and product mix.

The KPI categories in ISO 22400

The standard organizes its indicators around the operational areas a shop actually manages:

• Production: throughput, allocation, utilization, setup, and effectiveness metrics.
• Quality: scrap ratio, rework ratio, first pass yield, and quality ratio.
• Maintenance: availability, mean time between failure (MTBF), mean time to repair (MTTR), and corrective versus preventive maintenance ratios.
• Inventory and logistics: work in process and inventory turn style measures.

Most discrete and tooling shops only need a handful of these to get started. The trap is measuring everything and acting on nothing.

The core metric: OEE and its three factors

The KPI almost everyone reaches for first is Overall Equipment Effectiveness (OEE). Under ISO 22400-2 it is a composite of three standardized factors:

OEE = Availability x Effectiveness x Quality Ratio

Each factor isolates a different kind of loss, and that is exactly what makes OEE useful. The score points you at the problem instead of just the symptom.

• Availability is the share of planned production time the equipment is actually running. ISO defines it as operating time divided by planned production time, which exposes downtime, breakdowns, and setups. Planned breaks are left out of the denominator.
• Effectiveness is the speed factor. It measures whether the machine runs at its theoretical cycle time, catching minor stops, slow running, and speed loss.
• Quality Ratio is the share of output that meets specification on the first pass. Rework counts as a quality loss, not as good parts.

A worked example: 90% availability x 95% effectiveness x 98% quality lands at roughly 84% OEE. The composite number is fine for trending, but the three factors are where the action is. A drop in availability and a drop in quality call for completely different responses.

One caveat worth knowing: ISO 22400-2 actually describes more than one way to calculate OEE (a primary version plus a Nakajima style version in an annex), and the two do not always agree. Pick one definition, document it, and apply it the same way across every asset.

Why ISO 22400 matters for job shops and tooling shops

Large plants adopt the standard to compare facilities. Smaller discrete manufacturers and tooling shops get a different, more immediate benefit: a shared language that survives growth.

When every operator logs downtime by the same definition, your data becomes auditable, comparable from shift to shift, and ready the day a customer or auditor asks how you measure performance. It also makes any future monitoring or dashboard rollout far smoother, because you are configuring a tool against agreed definitions instead of inventing them halfway through the project.

From definition to live number: how to actually use it

A standardized KPI is worthless if it lives in a spreadsheet that is already a day old. The path to value looks like this:

1. Pick a small set of KPIs tied to a real goal, usually OEE and its three factors plus one quality and one maintenance metric.
2. Lock down the definitions using ISO 22400-2 so "downtime," "good part," and "planned time" each mean one thing across the shop.
3. Capture the data automatically from the machines, not from memory at the end of the shift.
4. Surface it where people make decisions, with live screens for operators and supervisors and clean summaries for managers.
5. Act on the factor, not just the headline score.

Steps 3 and 4 are where most ISO 22400 efforts stall, and they are exactly what R.E.R. Software's InFocus platform is built to handle. AutoTrack captures machine status and downtime automatically, feeding availability and effectiveness with real signals instead of operator guesswork. For the bigger picture, see our guides to production monitoring software and machine downtime. Custom Dashboards render OEE and its factors live, on the floor and in the office. Smart Alert flags a falling availability number before it turns into a missed order, and AutoPlan turns those same signals into schedules your shop can actually hit.

Common ISO 22400 pitfalls to avoid

• Subtracting setup from the denominator. Changeover is a true availability loss, not "planned" time. Leave it in.
• Counting rework as good parts. Only first pass conforming output counts toward Quality Ratio.
• Using the wrong cycle time. Use the design or best demonstrated cycle for Effectiveness, never the average actual.
• Averaging OEE across unlike lines. Comparing machines with different cycle times distorts the result. Compare per asset or weight by value.
• Confusing OEE with TEEP. OEE uses planned production time as its base. TEEP uses calendar time (24/7) and is always lower. Do not mix the two.

Put ISO 22400 to work on your floor

A standard is only as good as the data behind it. If you are ready to move OEE and its factors out of spreadsheets and onto live screens your team trusts, see how R.E.R. Software's InFocus platform turns machine signals into standardized KPIs, or contact us to map ISO 22400 metrics to your specific equipment.