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ISO 22400 Basics: Core Definitions, KPI Concepts, and Terminology
ISO 22400 gives aerospace manufacturers a shared language for talking about performance. Instead of each plant defining its own version of “availability” or “equipment utilization,” the standard describes how key performance indicators (KPIs) should be structured and interpreted for manufacturing operations management (MOM). It does not tell you which KPIs to use or what “good” looks like; it defines what those KPIs mean.

For aerospace and defense programs running across multiple sites, partners, and tiers of the supply chain, this common vocabulary matters. It makes it possible to compare the performance of a nacelle line in one region with a composite structures cell in another using consistent terms. Platforms like Connect 981 use these ISO 22400 manufacturing KPI concepts as a neutral layer so MES, ERP, QMS, and engineering systems can exchange performance data without semantic confusion.

What ISO 22400 Tries to Standardize (and Why It Matters)

ISO 22400 focuses on the conceptual side of manufacturing KPIs. It defines the building blocks, categories, and relationships behind performance indicators used in MOM environments. For aerospace plants, that means the terms used in OEE dashboards, turnaround-time reports, and shop-floor status boards can be interpreted consistently from program to program and site to site.

The role of common KPI language in multi-site manufacturing

In a typical aerospace enterprise, different facilities may have grown up with local KPI dialects. One final assembly line might report “uptime,” a composites facility reports “machine availability,” and an MRO shop tracks “bay occupancy.” Without shared definitions, leadership cannot be sure whether numbers are directly comparable, even when they use similar words.

ISO 22400 addresses this by standardizing:
- How performance indicators and KPIs are defined conceptually
- How time, quantity, and state concepts relate to each other
- Which attributes a KPI description should include (purpose, unit, time behavior, users, trend direction, and so on)
For aerospace programs with stringent regulatory and contractual obligations, this consistency underpins reliable reporting to airframers, defense agencies, and aviation authorities. When contracts reference KPIs that align with ISO 22400 terminology, disputes about “what was actually measured” become less likely.

How ISO 22400 fits into the standards landscape (IEC 62264, etc.)

ISO 22400 sits alongside other standards that describe how an aerospace factory’s digital infrastructure is organized. IEC 62264 (and its ISA-95 lineage) defines integration between enterprise systems (planning, finance) and control systems (equipment, cells, lines). It introduces levels such as enterprise, site, area, work center, and work unit.

ISO 22400 aligns its KPI concepts with these levels, focusing primarily on what IEC 62264 calls Level 3: manufacturing operations management. That is where MES, dispatching, detailed scheduling, and WIP tracking live. In practice, this means:
- KPIs are defined at the same structural levels you use for routing, work centers, and work units in MES
- Performance data exchanges between MES, ERP, QMS, and data historians can reference a common hierarchy
- Plant-level reports and program-level summaries can be tied back to standard, named KPI concepts
For regulated aerospace environments, this alignment simplifies building traceable, auditable flows of performance information across planning, execution, and reporting systems.

Core Performance Measurement Concepts in ISO 22400

ISO 22400 starts by clarifying the basic elements of performance measurement in manufacturing. If your teams use these terms consistently, integration projects and cross-plant benchmarking become far simpler.

Performance indicators vs. key performance indicators

The standard makes a clear distinction between “performance indicators” and “key performance indicators”:
- Performance indicator: any measurable quantity or relationship that characterizes how a process, resource, or order behaves. Examples in aerospace include time an autoclave spends in RUN state, number of accepted parts after inspection, or hours spent on unplanned rework.
- Key performance indicator (KPI): a selected subset of those indicators judged critical for understanding performance and steering operations. KPIs are not just raw numbers; they are indicators that have been named, described, and contextualized.
In ISO 22400 terms, a KPI comes with a conceptual description: what object it applies to (equipment, line, order), which time horizon it covers (shift, day, campaign), its intended users (operators, supervisors, management), and the expected trend direction (higher is better, lower is better, target band, and so on).

For an aerospace composite layup cell, “time in oven RUN state” is a performance indicator. “Oven utilization for autoclave A23 during the last shift,” normalized against planned time and described per ISO 22400, can be treated as a KPI.

From raw signals to derived indicators to KPIs

ISO 22400 also introduces a layered view of how performance data is built:
- Raw signals: direct outputs from control systems or sensors, such as machine ON/OFF, RUN/STOP state codes, part count increments, or temperature readings.
- Derived indicators: values computed from raw signals, like time in a given state, quantities produced per period, or counts of changeovers for a work unit.
- KPIs: standardized constructs created from one or more derived indicators, aligned with ISO 22400 terminology and attributes.
Consider an aerospace drilling cell producing wing skins. PLC data shows RUN, IDLE, and STOP states plus part counters. The MES aggregates these signals into derived indicators: total RUN time during a shift, number of completed skins, scrap count. ISO 22400 then provides a conceptual pattern for defining a KPI like “equipment utilization for drilling cell 4,” based on those derived indicators, with a clear description of what time buckets and quantities it uses.

This separation is important in aerospace programs with mixed equipment vintages and multiple MES instances. Different equipment can produce different raw signals, yet you can still converge on common KPIs as long as the derived indicators and definitions follow ISO 22400 patterns.

Defining Manufacturing Operations Management (MOM)

Manufacturing operations management (MOM) is central to ISO 22400. The standard uses MOM as the context in which KPIs are defined and interpreted.

MOM in relation to ERP and control systems

In an aerospace factory, enterprise resource planning (ERP) handles contracts, customer orders, high-level capacity planning, and financials. At the other end of the stack, control systems operate equipment, collect signals, and enforce process parameters on machines, cells, and test stands.

MOM sits between these layers and includes functions typically associated with MES and related systems:
- Dispatching work orders and operations to the shop floor
- Tracking WIP status for assemblies, subassemblies, and components
- Recording execution data such as start/stop times, scrap counts, and test results
- Coordinating maintenance, tool availability, and material readiness
ISO 22400 KPIs are designed primarily for this MOM layer, where execution decisions are made and where aerospace-specific constraints—such as serialized component tracking, configuration control, and inspection holds—are applied.

Typical MOM activities covered by ISO 22400

The standard spans several functional areas that matter for regulated aerospace production:
- Production operations: order execution, sequencing, changeovers, resource allocation to work units and lines.
- Maintenance operations: planned and unplanned maintenance, equipment readiness, impact of downtime on critical production assets.
- Quality operations: inspection, test, containment, and disposition activities that affect throughput and scrap/rework.
- Inventory and logistics operations: internal material flows, staging, and WIP movement that influence lead time and work center loading.
In each area, ISO 22400 emphasizes that performance indicators should be defined against a clear object (equipment, order, resource) and time context. For example, a KPI that measures the execution reliability of a batch of flight-critical actuators must explicitly state whether it is computed per production order, per work center, or per plant, and over what time base.

Key ISO 22400 Terms Manufacturers Should Know

Adopting ISO 22400 terminology starts with a few core concepts that show up repeatedly in MOM KPIs. For aerospace teams, these terms form the backbone of performance conversations between operations, engineering, and program leadership.

Availability, utilization, and equipment effectiveness

ISO 22400 devotes significant attention to equipment-focused measures because they underpin many shop-floor dashboards:
- Availability: conceptually, how much of the planned time a resource is actually in a state where it can produce. Downtime—both planned (e.g., scheduled maintenance) and unplanned—reduces availability.
- Utilization: how much of the available capacity is actually used. A machining center might be available but idle because material is missing or an operator is reassigned to another line.
- Equipment effectiveness: an aggregate concept capturing availability, performance (speed or throughput against a reference), and quality (proportion of good output). ISO 22400 describes several OEE-related models using standardized time and quantity elements.
On a composite layup line, availability might be constrained by autoclave maintenance, while utilization is limited by tooling readiness or cure cycle sequencing. Using ISO 22400 definitions helps isolate which aspect of performance is actually being affected and avoids conflating downtime with underutilization.

Work unit, production order, and state definitions

The standard also formalizes several structural and state-related terms that are particularly relevant when harmonizing KPIs across an aerospace digital thread:
- Work unit: the smallest functional production entity considered for MOM KPIs. In aerospace, this might be a specific machine (5-axis mill), a cell (drilling and fastening station), or even a test rig.
- Production order: an instruction to produce a defined quantity of a given configuration—such as a set of serialized landing gear components or a batch of engine brackets—often linked back to ERP or program planning.
- Equipment state: the abstracted condition of a work unit, such as RUN, STOP, IDLE, or SLOW. ISO 22400 uses these states as the basis for time categorizations that feed many KPIs.
State definitions matter because they determine how time is allocated across availability, utilization, and other indicators. For example, if an aircraft structure assembly station is IDLE because an engineering change is being evaluated, ISO 22400-based time models need a consistent way to classify that state—so that program reports differentiate engineering holds from pure equipment downtime.

How Clear Terminology Enables Better KPI Governance

Once terminology is aligned, aerospace organizations can treat KPIs as governed data assets rather than ad hoc report outputs. Governance is critical in environments where regulators, customers, and internal stakeholders all depend on consistent, traceable performance information.

Reducing ambiguity in internal and supplier reporting

Without standardized terminology, the same label can hide different calculation methods. One site might exclude quality holds from availability; another might include them. Over time, such inconsistencies undermine confidence in enterprise dashboards and supplier scorecards.

By adopting ISO 22400 terminology, you can:
- Specify unambiguous definitions for KPIs in internal reporting standards
- Clarify which time categories and states are included in each indicator
- Ensure that plant-level and supplier-level reports are structurally comparable
For example, a supplier delivering composite subassemblies can be required to report “equipment utilization for autoclaves” following an ISO 22400-aligned definition. This lets the prime contractor compare utilization patterns across multiple suppliers and internal sites without interpreting each data set from scratch.

Using ISO 22400 terms in contracts and SLAs

In aerospace contracts, words like “on-time completion,” “turnaround time,” and “line availability” often appear in service-level agreements (SLAs). If each party interprets these differently, disagreements multiply when performance is questioned.

ISO 22400 provides a neutral vocabulary that can be referenced in:
- Long-term agreements with tier-1 and tier-2 suppliers
- Maintenance and MRO contracts defining hangar or test stand performance
- Internal service agreements between central functions (e.g., shared coating facilities) and individual programs
By citing standard-aligned KPI definitions in these documents, aerospace organizations can make performance clauses more objective and auditable, while still tailoring thresholds and targets to the specific program or asset class.

Practical Next Steps for Adopting ISO 22400 Vocabulary

Adopting ISO 22400 terminology does not require redesigning every dashboard. It typically starts with clarifying language, then incrementally mapping existing indicators into standard-aligned structures.

Creating internal KPI glossaries and data dictionaries

A practical first move is to build an internal KPI glossary and data dictionary aligned with ISO 22400 concepts. For each KPI already in use—such as “autoclave availability,” “test stand OEE,” or “order execution reliability for flight control actuators”—document:
- The object of measurement (work unit, work center, order, plant)
- The time horizon (shift, day, rolling week, campaign)
- The underlying time buckets and quantities used in the calculation
- How state codes from control systems map to ISO 22400 states
This documentation helps engineering, production, and IT teams understand where definitions diverge from the standard and where they already align. In an AS9100 environment, such a dictionary can be treated as a controlled document, supporting auditability and change control for performance metrics themselves.

Aligning existing KPI names to ISO 22400 concepts

Most aerospace manufacturers already track a rich set of metrics in MES, QMS, and reporting tools. The challenge is not inventing new KPIs but realigning names and definitions with ISO 22400 so performance data becomes interoperable across systems and sites.

Typical steps include:
- Grouping existing metrics into ISO 22400 categories (equipment-oriented, order-related, resource-related)
- Identifying where multiple names refer to the same concept and consolidating them under a standard term
- Flagging metrics that mix conceptual dimensions (e.g., combining availability and quality into a single opaque index) and breaking them into clearer indicators
- Updating integration specifications so data exchanges use ISO 22400-aligned identifiers and descriptions
A platform like Connect 981 can help by providing a common data model that maps plant-specific tags and labels into ISO 22400 concepts. This lets existing systems retain local naming conventions, while enterprise-level analytics and cross-program dashboards work with a standardized vocabulary.

How ISO 22400 Relates to Other Levels and Standards

ISO 22400 does not operate in isolation. It is designed to slot into the layered model of manufacturing systems defined by IEC 62264 and related standards, particularly around MOM (Level 3) activities.

Hierarchy levels and KPI focus

Within the IEC 62264 hierarchy, ISO 22400 focuses on KPIs that live primarily at the MOM level:
- Level 4 (enterprise planning): business KPIs tied to financial results, customer service, and long-term capacity are largely out of scope.
- Level 3 (MOM): the core scope for ISO 22400 KPIs, where production, quality, maintenance, and inventory operations are planned and executed.
- Levels 0–2 (control and equipment): raw signals and control logic are not standardized by ISO 22400, but they feed the derived indicators and KPIs defined at Level 3.
In practice, this means aerospace organizations can use ISO 22400 to harmonize the KPI layer of their digital manufacturing infrastructure, even when they use different vendors, architectures, or deployment models at the control or enterprise levels.

Limits of KPI standardization in regulated environments

ISO 22400 deliberately avoids prescribing calculation formulas, performance targets, or improvement methods. This is especially important in regulated aerospace contexts, where organizations must tailor KPIs to program-specific requirements, regulatory frameworks, and risk profiles.

The standard does not decide:
- Which KPIs are mandatory for a given aircraft program or defense platform
- What thresholds define acceptable performance or trigger escalation
- How KPIs feed into incentive schemes or continuous improvement initiatives
Instead, ISO 22400 defines terminology and structures. Aerospace manufacturers, MRO organizations, and system integrators then layer their own domain-specific metrics—such as turnaround time breakdowns, concession rates, or first-pass yield for flight-critical assemblies—on top of that vocabulary. Where those metrics overlap with ISO 22400 concepts, the standard provides a clean way to describe them; where they are unique, they can coexist without being misrepresented as ISO 22400 KPIs.

ISO 22400 in a Connected Aerospace Manufacturing Environment

Aerospace production and MRO facilities rely on a complex ecosystem of digital systems: ERP for contracts and orders, PLM for product definitions and configurations, MES for execution, QMS for nonconformance and corrective actions, and historians or data lakes for time-series data. ISO 22400 offers a neutral KPI layer that can bind these systems together.

In this environment, a standard-aligned KPI model helps ensure that when a program manager views a dashboard combining OEE data from machining, yield data from inspection, and schedule adherence from planning, every number is grounded in consistent meaning.

Data integration and interoperability benefits

From an integration perspective, ISO 22400 supports:
- Common naming: interface specifications can use standardized KPI identifiers, reducing ambiguity when systems are integrated or replaced.
- Stable semantics: as plants modernize equipment, underlying raw signals can change without forcing a redefinition of KPIs, as long as the derived indicators still align with ISO 22400 concepts.
- Traceability of performance data: KPI definitions can be treated like other controlled data artifacts in the digital thread, supporting audits and investigations.
For example, when a new MES is rolled out to a wing assembly plant, the integration team can map its event codes and counters to existing ISO 22400-aligned KPIs, maintaining continuity for enterprise reports and supplier scorecards.

Connect 981’s role in applying ISO 22400 concepts

As a digital manufacturing platform focused on aerospace and regulated production, Connect 981 can implement ISO 22400 terminology as a shared reference layer. While each organization retains its own KPI choices and targets, the platform can:
- Map equipment states, order events, and inspection results into ISO 22400-aligned indicators
- Link KPIs to serialized components and configurations, preserving part genealogy and performance context
- Expose standard-aligned KPI definitions to downstream analytics and reporting tools
This approach supports cross-program visibility without forcing every plant or supplier to abandon their existing systems. The key is that wherever KPIs appear—in shop-floor dashboards, supplier portals, or executive summaries—their underlying terminology is consistent with ISO 22400.

Summary: Using ISO 22400 Terminology to Strengthen KPI Foundations

ISO 22400 gives aerospace manufacturers a rigorous language for describing manufacturing KPIs. It clarifies the distinction between raw signals, derived indicators, and KPIs; defines core terms like work unit, equipment state, availability, and utilization; and aligns MOM-level metrics with the broader enterprise-control hierarchy.

The standard does not replace organizational strategy or sector-specific metrics. Instead, it offers a common foundation so that performance data from diverse plants, partners, and systems can be interpreted consistently. For aerospace organizations operating in AS9100 and similar regulated environments, adopting ISO 22400 terminology supports clearer contracts, more reliable cross-site comparisons, and stronger data governance across the digital thread. Platforms such as Connect 981 can then apply this vocabulary across MES, QMS, ERP, and engineering systems, turning performance measurement into a coherent, standards-aligned capability rather than a collection of disconnected local practices.

Note: This article is an educational overview of ISO 22400 concepts in the aerospace manufacturing context. It does not reproduce the standard text or replace the need to consult the official ISO 22400 documents.
March 2, 2026
ISO 22400 Explained: A Practical Guide to Standardized Manufacturing KPIs
Answer first: ISO 22400 is an international standard that defines how manufacturing key performance indicators (KPIs) are described, structured, and named so that plants, suppliers, and systems can talk about performance in the same language. It does not tell you which KPIs to use, what targets to set, or how to run improvement programs. Its job is to define what the metrics mean, not how you manage with them.

This overview explains the basics of ISO 22400 in plain language for operations, IT, and quality leaders. By the end, you should understand why the standard exists, what it covers (and doesn’t), and how its KPI concepts differ from homegrown definitions you may use today. If you later decide to build a standardized ISO 22400 KPI framework, you will know what role the standard can realistically play.

Why ISO 22400 Exists in Modern Manufacturing

The problem of inconsistent KPI definitions across plants

Many manufacturers grow through acquisitions, greenfield sites, and long supplier networks. Over time, each plant develops its own metrics and naming conventions. Common situations include:
- One site tracks “availability” while another tracks “uptime,” but they include different kinds of downtime.
- OEE is calculated differently between plants, making comparisons misleading.
- Corporate dashboards aggregate numbers that were never defined in the same way.
The result is confusion. Leaders spend time debating what the numbers mean instead of discussing how to improve them. ISO 22400 exists to reduce this definitional noise.

How global supply chains and heterogeneous systems increase confusion

Modern operations rely on a mix of systems: ERP for planning, MES for execution, SCADA and PLCs for control, historians for time-series data, and various reporting tools. Each system may:
- Use its own KPI names and abbreviations
- Define equipment states in different ways
- Aggregate time and quantity data according to its own rules
When you connect multiple sites and suppliers, these inconsistencies multiply. A KPI that looks identical on a dashboard may be based on very different underlying logic. ISO 22400 addresses this by defining a shared conceptual framework for KPIs used in manufacturing operations management.

Standards as a common language for performance data

ISO 22400 belongs to the family of automation and integration standards. Its purpose is to provide a common language for performance data so that:
- Plants can compare performance on consistent terms
- Suppliers and customers can refer to the same KPI definitions in contracts and reports
- Software vendors can design interfaces that exchange KPI information without custom translations for every project
This language is intentionally industry neutral, so discrete, batch, and continuous operations can all use the same conceptual building blocks.

What ISO 22400 Covers—and What It Does Not

Conceptual KPI definitions and terminology

ISO 22400 focuses on the conceptual side of performance measurement. It defines:
- Core terms such as performance indicator, key performance indicator (KPI), work unit, production order, and equipment state
- Attributes that describe KPIs, for example:
  - What object is being measured (equipment, order, plant, etc.)
  - Which time behavior applies (real time, shift, order lifecycle)
  - Which units of measure and trend directions make sense
- Families of KPIs for production, maintenance, quality, logistics, and energy-related operations
The standard separates indicators into a broader set of performance indicators and a more selective set of key performance indicators. The key indicators are those considered particularly relevant for monitoring manufacturing operations.

Relationship to enterprise-control integration standards (IEC 62264)

ISO 22400 is closely aligned with IEC 62264, the reference standard for enterprise-control system integration. IEC 62264 defines hierarchical levels such as:
- Level 4 – Business planning and logistics (ERP layer)
- Level 3 – Manufacturing operations management (MOM)
- Levels 0–2 – Basic control and equipment
ISO 22400 positions its KPIs mainly at Level 3, the manufacturing operations layer. This is where production, quality, inventory, and maintenance are executed and monitored. Metrics that combine detailed operational data with financial results at Level 4 typically fall outside the scope of ISO 22400.

Boundaries: no targets, formulas, or improvement methods

Understanding what ISO 22400 does not do is as important as understanding what it covers. The standard deliberately avoids:
- Prescribing KPI formulas: It may describe the time and quantity elements involved in a KPI, but it does not dictate a single calculation method.
- Setting targets or thresholds: No “good” or “bad” values are defined. Targets depend on your industry, equipment, and strategy.
- Describing improvement techniques: Lean, TPM, Six Sigma, and other methods are outside its remit.
If you adopt ISO 22400, you still decide which KPIs to track, what levels to report them at, and how to use them in decision-making. The standard provides vocabulary and structure, not a performance playbook.

Key Concepts in ISO 22400

Performance indicators vs. key performance indicators

ISO 22400 separates the universe of possible measures into:
- Performance indicators: Any quantified measure that describes how a resource, process, or system behaves. Example: total time a machine spent in RUN state during a shift.
- Key performance indicators (KPIs): A selected subset of indicators that are considered especially important for managing manufacturing operations. Example: equipment utilization for a bottleneck work center.
The standard provides a structured description for KPIs, including their intended users (operator, supervisor, manager), applicable time horizons, and typical use cases. This helps organizations distinguish between raw data, general metrics, and the smaller group of measures that truly drive decisions.

Manufacturing operations management (MOM) and Level 3 focus

In the ISO 22400 context, Manufacturing Operations Management (MOM) refers to the activities that plan, dispatch, execute, track, and report manufacturing and maintenance operations. MOM sits between enterprise planning systems and the shop-floor control layer.

ISO 22400 focuses on KPIs relevant to this MOM layer, such as:
- Production order execution and adherence to plan
- Equipment availability and utilization
- Quality-related outcomes linked to production
- Maintenance-related states and their impact on production
By concentrating on Level 3, the standard builds a bridge between high-level business goals and detailed control-system data.

Objects of measurement: equipment, orders, plants, and more

Another core concept in ISO 22400 is the object of measurement. KPIs are always tied to something being measured, for example:
- Equipment and work units: Individual machines, workstations, or cells
- Lines and areas: Production lines, work centers, or plant areas
- Production orders and lots: Specific orders, batches, or serial ranges
- Entire sites: Plant-level aggregates
The same conceptual KPI—such as equipment utilization—can be applied at different levels. ISO 22400 clarifies how these KPIs relate to time, quantity, and state concepts so that aggregation across levels is meaningful.

How ISO 22400 Helps Multi-Site and Multi-Supplier Operations

Comparability across plants and suppliers

For organizations operating multiple plants or collaborating with external manufacturers, comparability is a key challenge. Without standard definitions, numbers for “availability,” “throughput,” or “scrap rate” may not be genuinely comparable.

By adopting ISO 22400 definitions:
- Corporate dashboards can present KPIs that are consistent across locations.
- Benchmarking between plants becomes more robust.
- Supplier scorecards can reference the same KPI terms with clear, shared meanings.
Instead of spending time reconciling definitions, teams can focus on understanding performance differences and root causes.

Interoperability across ERP, MES, SCADA, and reporting tools

Most manufacturers do not have a single monolithic system. Instead, they integrate ERP, MES, SCADA, historians, and specialized reporting tools. ISO 22400 supports this heterogeneous reality by providing:
- Standard terminology for equipment states and time categories
- Consistent KPI names and attributes
- A conceptual structure that data models can reference
When multiple systems use ISO 22400-aligned definitions, data exchange and aggregation become easier. Interfaces can be designed around shared KPI concepts rather than custom mappings for each integration.

Using standardized KPI definitions in contracts and SLAs

Another practical benefit appears in commercial relationships. When performance reporting is part of a contract or service-level agreement (SLA), unclear metric definitions can lead to disputes.

By referencing ISO 22400 concepts in contracts—for example, defining “equipment utilization” or “order execution reliability” according to the standard—both parties can verify they are using the same language. This reduces ambiguity and supports more transparent, data-driven collaboration.

Deciding Whether ISO 22400 Is Right for Your Organization

Typical adopters: discrete, batch, and process industries

ISO 22400 is intentionally industry neutral and can be applied in:
- Discrete manufacturing: Aerospace, electronics, industrial machinery, and precision component manufacturing
- Batch processes: Chemicals, pharmaceuticals, food and beverage
- Continuous processes: Oil and gas, utilities, large-scale chemical plants
Organizations with complex multi-site operations, regulated environments, or extensive supplier networks often benefit most from a standard KPI language.

Signs your KPI landscape needs standardization

Consider ISO 22400 if you recognize several of the following symptoms:
- Different plants use the same KPI names but calculate them in incompatible ways.
- Corporate reports are built through manual reconciliation of spreadsheets from each site.
- Discussions about performance frequently turn into debates about “what the numbers mean.”
- New system implementations require bespoke KPI definitions every time.
- Supplier performance reviews spend more time clarifying definitions than discussing outcomes.
In such environments, a standardized conceptual framework can simplify reporting and improve the quality of performance discussions.

Combining ISO 22400 with domain-specific KPIs

Even if you adopt ISO 22400, you will likely need additional, domain-specific measures. Examples include:
- Aerospace traceability indicators tied to serial numbers and life-limited parts
- MRO turnaround-time breakdowns specific to overhaul workflows
- Regulatory compliance metrics unique to pharmaceuticals or medical devices
The key is to distinguish clearly between KPIs that follow ISO 22400 definitions and those that are custom to your organization. Many platforms and data models allow you to label metrics accordingly, so users know which indicators are standardized and which are local extensions.

Next Steps: Moving From Awareness to Adoption

Assessing your current KPI definitions

Before changing tools or rolling out new dashboards, start with a structured assessment of your existing KPIs:
- Compile your current KPI catalog across plants and systems.
- Document how each metric is defined, including included and excluded time or quantity elements.
- Identify where different sites use the same names for different concepts—or different names for the same concept.
This inventory will show where ISO 22400 can bring the most immediate clarity.

Prioritizing which domains to standardize first

You do not need to implement every ISO 22400 concept at once. Many organizations begin by focusing on a subset of domains, such as:
- Equipment-related KPIs for critical work centers or bottlenecks
- Order execution KPIs for key value streams or product families
- Quality-related KPIs tied to high-risk or high-cost defects
Starting small and expanding over time reduces disruption and helps teams build confidence in the standardized definitions.

How ISO 22400 concepts support platforms like the hub

Modern digital operations platforms can use ISO 22400 concepts as a semantic layer between shop-floor events and business reporting. For example, a platform aligned with the ISO 22400 Manufacturing KPIs: Standardized Performance Measurement for Modern Plants hub can:
- Map raw signals and equipment states to ISO 22400-aligned time categories.
- Expose standardized KPI definitions across ERP, MES, PLM, QMS, and analytics tools.
- Allow additional, non-standard KPIs to coexist without being mislabeled as ISO 22400 measures.
In this way, the standard becomes an enabler of consistent reporting rather than a constraint on how you design your operations.

Summary: What ISO 22400 Means for Manufacturing KPIs

ISO 22400 is a definitional standard for manufacturing KPIs. It offers:
- A clear distinction between performance indicators and key performance indicators
- A focus on manufacturing operations management (Level 3)
- Standard terminology for equipment, orders, and plant-level KPIs
- Alignment with IEC 62264 for enterprise-control integration
Equally important, it does not dictate which KPIs you must use, how to calculate them in detail, what targets to set, or how to run improvement programs. Those remain business decisions.

If your organization struggles with inconsistent KPI definitions across plants, systems, or suppliers, ISO 22400 can provide a solid foundation for a more coherent performance measurement framework. From there, you can build dashboards, analytics, and contracts on top of a shared understanding of what the numbers mean—while retaining the flexibility to add domain-specific metrics where needed.
March 2, 2026
Aerospace Non-Conformance Reports (NCRs): Step-by-Step Process and Best Practices
Aerospace Non-Conformance Reports (NCRs): Step-by-Step Process and Best Practices

In aerospace, a single non conformance can ground an aircraft, trigger regulatory scrutiny, or delay a key delivery. That is why the aerospace non conformance report process must be structured, repeatable, and fully traceable from first detection through final closure.

This article explains the aerospace non conformance report (NCR) lifecycle in practical terms. You will see what information belongs in an NCR, how work should flow between quality, engineering, production, and suppliers, and where digital tools can eliminate delays and blind spots. For a broader view of how NCRs fit into the wider quality ecosystem, see our hub article on aerospace non conformance management.

What Is an Aerospace Non-Conformance Report (NCR)?

Definition of an NCR in Aerospace Manufacturing and MRO

An aerospace non-conformance report (NCR) is a formal record used to document any deviation from approved requirements in design, manufacturing, maintenance, repair, or overhaul activities. It captures the details of the discrepancy, its impact, and the actions taken to contain, investigate, and disposition the issue.

In AS9100-based quality systems, NCRs are a primary mechanism for demonstrating control of nonconforming product and for feeding issues into corrective action and continuous improvement processes.

Common Triggers for Raising an NCR

Typical triggers for issuing an NCR in aerospace include:
- Dimensional out-of-tolerance conditions identified during inspection
- Incorrect material, heat treatment, or special process certification
- Surface defects such as scratches, pits, corrosion, or coating damage
- Assembly errors (wrong part installed, incorrect torque, missing hardware)
- Software or configuration mismatches relative to the approved baseline
- Deviations from approved work instructions or process parameters
- Equipment used past calibration or outside specified limits
- Field or in-service performance issues reported by operators or customers
Any time product, documentation, or process execution does not conform to the approved specification or procedure, an NCR should be raised to preserve traceability and ensure structured follow-up.

Minor vs. Major Non Conformances and Risk Categorization

Aerospace organizations typically categorize non conformances according to risk. Terminology and criteria may be defined by internal procedures, AS9100-compliant QMS documents, customer contracts, or regulatory expectations, so each organization must follow its own approved definitions. A common pattern is:
- Minor non conformance: A deviation that does not affect safety, airworthiness, form/fit/function, or regulatory compliance. Examples include cosmetic blemishes within agreed limits or certain documentation errors that can be corrected without product impact.
- Major non conformance: A deviation that may affect safety, airworthiness, performance, reliability, or compliance. Examples include dimensional issues on critical features, missing inspections, process escapes on special processes, or unapproved design changes.
Risk categorization helps determine priorities, containment urgency, who must approve dispositions, and which NCRs must be reported to customers or authorities.

Core Stages of the Aerospace NCR Process

While each organization’s procedures differ, most aerospace NCR workflows contain the same core stages.

1. Detection and Initial Documentation

The process starts when someone detects a deviation. This might be an inspector, production technician, engineer, supplier quality representative, or field service technician. Key steps include:
- Recognize the non conformance: Confirm that an actual requirement is violated (drawing, specification, procedure, or contract).
- Open the NCR: Create an NCR record in the approved system with a unique identifier.
- Capture basic details: Part number, serial/lot, work order, operation, discrepancy description, and who found it.
- Record immediate risk notes: Is product already delivered? Is there potential impact to in-service aircraft?
Fast, accurate initial documentation is essential. Incomplete information at this stage often causes rework and investigation delays later.

2. Containment and Segregation of Nonconforming Product

Containment prevents the nonconformance from spreading or reaching the customer. Typical actions:
- Physically segregate affected parts or assemblies in a clearly marked hold area.
- Place electronic or physical hold tags on related work orders or lots.
- Stop or limit production steps that could worsen the issue.
- Assess potential impact on delivered product or fielded aircraft and initiate additional containment if required.
The objective is to protect flight safety and customer operations while the investigation proceeds. The effectiveness and timeliness of containment are key metrics for a healthy NCR process.

3. Root Cause Investigation and Analysis

Once the situation is stable, a structured investigation begins. Common practices include:
- Assign an owner: Typically a quality or manufacturing engineer responsible for coordinating the investigation.
- Use a formal method: 5-Why, Ishikawa/fishbone, 8D, or similar approaches suitable for aerospace applications.
- Consider multiple cause categories: Human (training, workload), method (procedure), machine (equipment), material, measurement, and environment.
- Review historical data: Previous NCRs, process capability data, maintenance logs, and supplier history to determine if the issue is isolated or systemic.
In aerospace, superficial root cause analysis is a recurring audit finding. Investigations must go beyond operator error and identify underlying system or process contributors.

4. Disposition, Corrective, and Preventive Actions

Disposition is the formal decision on what to do with the affected product. Common aerospace dispositions are:
- Use-as-is: The product is acceptable in its current state, and engineering analysis confirms no negative impact to form, fit, function, or safety.
- Rework: The product will be processed to bring it fully back into conformance with the original specification.
- Repair: A controlled deviation from the original design is accepted according to an approved repair scheme, often documented in a repair order or engineering deviation.
- Scrap: The product is not recoverable or is not economical to rework or repair and is permanently removed from use.
Around the disposition decision, the team defines:
- Immediate corrective actions: What must be done now to fix the specific occurrence.
- Systemic corrective actions: Changes to procedures, tooling, training, or controls to address the root cause.
- Preventive actions: Proactive measures to prevent similar issues in adjacent processes or products, even if they have not yet failed.
Who can approve which disposition is usually defined by internal procedures and may depend on part criticality, regulatory requirements, and customer contracts.

5. Verification and Formal Closure

An NCR should only be closed when:
- The disposition has been implemented and documented.
- All required inspections, tests, or verifications are completed.
- Corrective and preventive actions are implemented and verified for effectiveness according to internal criteria.
- All required approvals and signatures are captured in the record.
Verification might include follow-up audits, review of process performance data, or sampling inspections after the corrective action is in place. Only then is the NCR closed in the system. The data should still be accessible for trend analysis, audits, and continuous improvement.

Standardizing NCR Data Capture

Standardizing the information captured in each non conformance report is one of the fastest ways to improve investigation quality and reduce cycle time.

Mandatory Fields: Part, Serial, Work Order, References

At minimum, an aerospace NCR should consistently record:
- Identification: Part number, nomenclature, revision level, and configuration baseline.
- Traceability: Serial number, lot/batch number, heat number (if applicable), and work order or routing.
- Location: Station, process step, or facility where the non conformance was found.
- References: Drawing or model ID, specification, procedure, or customer requirement that was violated.
- Detection method: Incoming inspection, in-process inspection, final inspection, test, or field report.
- Discrepancy description: Clear, objective description including what was expected vs. what was actually observed.
Many organizations define checklists or electronic forms to ensure these data elements cannot be skipped.

Capturing Visual Evidence and Measurement Data

High-quality NCRs include objective evidence, such as:
- Photographs of the condition with clear context and scale
- Dimensional measurements compared to tolerance bands
- Screen captures or logs from test systems and automated equipment
- Copies or links to relevant certifications, travelers, or process records
Digital systems make it easier to attach this evidence directly to the NCR, improving communication between inspectors, engineers, and suppliers.

Ensuring Completeness at the Point of Entry

Data gaps at the start of the process are a major cause of NCR delays. To minimize this:
- Use mandatory fields with validation rules in electronic forms.
- Provide clear guidance and training for personnel who open NCRs.
- Leverage dropdown lists for common defect codes and locations to standardize terminology.
- Integrate with ERP/MES to auto-populate part, work order, and customer data where possible.
Doing the hard work upfront enables faster, more accurate root cause work later on.

Roles and Responsibilities Across the NCR Workflow

Quality Engineering Ownership

Quality often owns the overall NCR process. Typical responsibilities include:
- Ensuring NCRs are opened when required and contain sufficient detail.
- Coordinating containment and verifying that affected product is controlled.
- Driving root cause analysis and ensuring use of structured methods.
- Monitoring timelines, escalations, and adherence to procedures.
- Maintaining the integrity of the NCR database and reporting.
Production, Design Engineering, and Supplier Roles

Beyond quality, other functions play key roles:
- Production / Operations: Implement containment and rework, provide process knowledge, and support root cause investigations.
- Manufacturing / Industrial Engineering: Analyze process capability, tooling, and workflow; propose process changes.
- Design Engineering: Evaluate impact to form/fit/function and safety, approve use-as-is or repair dispositions, and initiate design changes when required.
- Supplier Quality and Suppliers: Investigate and correct issues originating at the supplier, provide supporting data, and implement corrective actions in their own processes.
Escalation Paths for Safety-Critical Issues

For safety-critical parts, systems, or in-service events, escalation paths must be clear and documented. These may include:
- Immediate notification of engineering leadership and airworthiness authorities within the organization.
- Triggers for reporting to customers according to contract or quality agreement clauses.
- Internal safety review boards or material review boards (MRBs) for high-risk dispositions.
Timelines, communication channels, and decision-making authority should be defined in approved procedures rather than improvised after a serious event occurs.

Common Bottlenecks in Manual NCR Processes

Email-Based Approvals and Spreadsheet Tracking

Many aerospace facilities still manage NCRs via email, shared folders, and spreadsheets. Typical consequences include:
- Approvals that sit in inboxes for days with no visibility to quality or management.
- Conflicting versions of NCR forms across various shared drives.
- Manual copying of data between systems, leading to errors and omissions.
These delays directly impact mean time to closure, on-time delivery, and audit readiness.

Lost Context and Incomplete Audit Trails

When conversations occur in email threads and hallway discussions, critical context is easily lost:
- Decisions are not fully documented in the NCR record.
- Investigations are difficult to reconstruct during audits.
- Lessons learned cannot be effectively reused across the organization.
Aerospace regulators and customers expect complete and retrievable records, not scattered files and partial histories.

Missed Deadlines for Customer and Regulatory Commitments

Some customers and authorities specify response times for acknowledging and resolving non conformances. Manual monitoring makes it easy to miss these commitments. Consequences can include:
- Formal audit findings or certification risk.
- Customer dissatisfaction and increased oversight.
- Pressure on internal teams as due dates slip without early visibility.
Without real-time dashboards and automated reminders, quality managers often spend significant time just chasing status updates.

Digitizing the NCR Workflow

Digital tools do not change the fundamental steps of the NCR process, but they dramatically improve speed, visibility, and consistency.

Configurable Electronic NCR Forms

Electronic forms allow organizations to:
- Standardize mandatory data fields for all NCRs.
- Configure specialized forms for different categories (e.g., design, supplier, in-service).
- Embed guidance, checklists, and drop-down codes to improve data quality.
- Attach supporting documents and multimedia evidence directly to the record.
This reduces errors and rework compared with handwritten or static PDF forms.

Automated Routing and Notification Rules

Workflow engines can route NCRs automatically based on criteria such as product line, customer, risk level, or part criticality. Typical capabilities include:
- Automatic assignment of NCRs to the responsible quality or engineering group.
- Parallel routing for approvals when multiple sign-offs are required.
- Escalation emails or alerts when tasks remain open beyond defined thresholds.
This reduces dependency on manual coordination and helps ensure issues progress steadily toward closure.

Dashboards for Tracking Open NCRs and Cycle Time

Digital dashboards give real-time visibility into:
- Total open NCRs by status, product line, or facility.
- Average and median cycle times.
- Backlogs at key workflow steps (e.g., pending engineering disposition).
- Top recurring defect codes, suppliers, or processes.
With this information, leaders can allocate resources, remove bottlenecks, and prioritize high-risk items proactively.

KPIs for Measuring NCR Process Performance

To continuously improve the aerospace non conformance report process, organizations track key performance indicators (KPIs) and use them in regular reviews.

Mean Time to Closure (MTTC)

Mean time to closure is the average time between NCR creation and final closure. It is often broken down by category, product family, or facility. Trends in MTTC help identify:
- Whether the process is becoming more efficient over time.
- Where specific groups or steps are causing delays.
- How process changes or digital tools are affecting responsiveness.
Some organizations also track time by phase (e.g., from detection to containment, from containment to disposition) for finer analysis.

First-Pass Containment and Investigation Effectiveness

It is not enough to close NCRs quickly; actions must be effective. Two useful concepts are:
- First-pass containment effectiveness: Percentage of non conformances where the initial containment fully prevents further escapes or rework.
- Investigation and corrective action effectiveness: Measured by repeat non conformance rates on the same part, process, or defect code over a defined period.
Low effectiveness often indicates that root causes were not correctly identified or that corrective actions were too narrow or insufficiently verified.

Rework, Scrap, and Cost of Poor Quality (COPQ) Impact

The NCR process should feed into cost analysis to support data-driven decision-making. Common metrics include:
- Rework hours and cost associated with NCRs.
- Scrap quantities and value by part family or process.
- Cost of Poor Quality (COPQ): A holistic measure including internal failure costs (rework, scrap), external failure costs (returns, concessions), appraisal costs, and prevention costs.
Linking technical NCR data with financial metrics helps prioritize improvement projects with the highest return on investment.

Connecting NCRs to Broader Non-Conformance Management

NCRs are a central building block of broader aerospace non conformance management. A mature approach:
- Integrates NCRs with CAPA, risk management, and configuration management processes.
- Supports trend analysis across multiple sites, programs, and suppliers.
- Ensures that lessons learned are shared and embedded into standards, training, and design rules.
By standardizing and digitizing the NCR process, aerospace organizations improve traceability, reduce cycle time, and protect safety and compliance, while building a stronger foundation for continuous improvement across their entire operation.
March 2, 2026