ISO 22400 gives aerospace manufacturers a shared vocabulary for key performance indicators (KPIs) in manufacturing operations, but it does not decide what “good” looks like in your plant. The standard defines concepts, structures, and naming conventions so that manufacturing data is comparable across systems and sites. Strategy, KPI selection, target-setting, and improvement methods remain the responsibility of each organization.
This article is for aerospace operations, quality, and compliance teams who need to understand ISO 22400 Scope and Limits: Where Strategy Begins and the Standard Ends. It explains the practical question this topic answers in a manufacturing execution context.
For aerospace and defense programs operating under AS9100, stringent configuration control, and multi-tier supplier networks, this boundary matters. You can align your data model and KPI semantics with the ISO 22400 manufacturing KPI framework while still tailoring metrics to specific aircraft platforms, engine programs, or space hardware contracts.
For teams putting this topic into daily operation, scrap and rework reduction, shop floor execution control, a connected execution platform help connect the concept to traceability, work-order reality, and audit-ready evidence.
The same operating model also depends on Connect981’s aerospace execution solutions, real aerospace execution examples, Connect981’s aerospace operations guidance, practical aerospace operations FAQs, especially when decisions have to move across quality, production, suppliers, and program leadership without losing context.
The Purposefully Narrow Scope of ISO 22400
ISO 22400 sits in the automation and integration family of standards. It is designed to let systems exchange performance information consistently, not to act as a performance management handbook. In practice, that means it emphasizes conceptual definitions over management practices.
Definitions and structures vs. business strategy
At its core, ISO 22400 defines what a KPI means in the context of manufacturing operations. It clarifies terms such as availability, utilization, work unit, production order, and equipment state. It also describes how KPIs relate to time, quantity, and event data, and where in the enterprise hierarchy they typically apply (work unit, line, area, site).
For an aerospace factory, this definitional layer becomes part of the digital thread. When a manufacturing execution system (MES), an ERP, and a quality system all use the same ISO 22400 definition of "equipment utilization" or "order execution reliability," KPI values remain comparable from a composite layup cell to a final assembly line, and across prime-supplier boundaries.
What ISO 22400 does not do is define your business strategy. It does not state that utilization is more important than schedule adherence for a given engine program, or that quality-related KPIs must carry more weight than throughput in a space hardware test facility. Those priorities are driven by contract risk, safety, regulatory expectations, and portfolio strategy.
Why the standard avoids prescriptive KPI sets
The standard includes a set of KPIs that are common across manufacturing, but it characterizes them as examples and reference concepts, not as a mandatory list. This is deliberate. A rigid KPI catalog would fit poorly across the diversity of aerospace operations—from composite fabrication and avionics assembly to engine overhaul and satellite integration.
By remaining neutral, ISO 22400 lets a single platform support:
- High-mix, low-volume prototype lines for new flight hardware.
- Rate-driven production of mature aircraft components.
- Maintenance, repair, and overhaul (MRO) shops with turn-time constraints and stringent traceability.
- Space system integration facilities with long-duration test campaigns.
The standard ensures shared meaning where concepts overlap, but expects each organization to extend or specialize the KPI set to reflect its aerospace-specific realities.
What ISO 22400 Does Not Standardize
The clearest way to understand ISO 22400 is to list what it intentionally leaves out. These omissions are not gaps; they are boundaries.
KPI selection, thresholds, and targets
ISO 22400 helps you define KPIs correctly, but it does not tell you which KPIs you must track. Selecting metrics is a strategic exercise that depends on product risk, customer contracts, and regulatory context. For example:
- A flight-control electronics line may prioritize first-pass yield, defect density per configuration item, and rework cycle time.
- A composite wing box cell may elevate cure cycle utilization, autoclave availability, and nonconformance rate per panel.
- An engine MRO line may center on turnaround time, work scope stability, and findings per shop visit.
Similarly, ISO 22400 does not define target values or alert thresholds. What counts as acceptable equipment utilization, schedule adherence, or scrap rate differs dramatically between prototyping and rate production, and between structural components and non-flight ground equipment.
Targets are shaped by:
- Contractual obligations and service levels.
- Certification and airworthiness considerations.
- Risk appetite and safety margins.
- Capital allocation and capacity plans.
The standard provides the KPI structure that you monitor against, but the "green/yellow/red" bands and escalation logic are defined by your own governance processes.
Improvement methodologies and incentive systems
ISO 22400 is not a continuous improvement framework. It does not describe how to interpret a declining OEE trend, how often to hold performance reviews, or how to design your daily management system. It stays neutral on whether you use lean, Six Sigma, theory of constraints, or internal methodologies.
Clarify the operational risk
When the work behind ISO 22400 Scope and Limits affects quality, delivery, or compliance, teams need one place to connect evidence, decisions, and shop-floor follow-through.
It also does not specify how KPIs should feed into incentive programs. For aerospace manufacturers, that boundary is important: tying bonuses directly to high-level KPIs without careful design can push teams toward behaviors that conflict with safety or compliance—for example, prioritizing throughput at the expense of rigorous configuration control. ISO 22400 leaves these choices to your leadership and HR policies; it only ensures that the data you base them on is consistently defined.
Handling Context-Dependent KPI Choices
Within aerospace and defense, context shifts quickly across programs and facilities. ISO 22400 acknowledges this by avoiding context-specific prescriptions. You must map its neutral definitions into your particular operating environment.
Discrete vs. process industries in aerospace
Many aerospace factories blend discrete and process characteristics. A composites facility may run autoclave cures (process-like), then trim and drill individual parts (discrete). ISO 22400 supports both kinds of behavior at the conceptual level: time states, order-related time structures, and quantity-based indicators can all apply.
However, you choose where to emphasize which KPIs. In a resin transfer molding line, cure time conformance and equipment state distribution may dominate. In avionics box assembly, order cycle time, WIP aging, and test yield may be more informative. The standard does not rank these for you; it simply gives you consistent language to capture them.
Regulated domains like aerospace and pharma
Highly regulated sectors such as aerospace, defense, and pharmaceuticals share concerns about traceability, documentation, and validation, yet ISO 22400 remains industry-neutral. It does not encode AS9100 requirements, FAA/EASA expectations, or export control constraints.
For an AS9100-compliant organization, that means you overlay regulatory and customer requirements onto the ISO 22400 framework. For example:
- You might extend order execution KPIs with metrics for inspection coverage, quality escape rate, or the proportion of operations executed under approved digital work instructions.
- You may track the latency between a detected nonconformance and containment actions, or between engineering change release and production adoption.
These are critical performance dimensions in aerospace, but they sit on top of, not inside, the ISO 22400 core concepts.
Granularity, Aggregation, and Reporting Decisions
ISO 22400 describes how KPIs can exist at multiple levels of the manufacturing hierarchy. It does not dictate which level is appropriate for which audience or decision.
Selecting levels (work unit, line, plant) per decision-maker
The standard aligns with hierarchy notions similar to enterprise, site, area, work center, and work unit. In aerospace operations, these are often mapped to:
- Work unit: a specific CNC machine, autoclave, test stand, or build station.
- Work center or line: a composite cell, harness assembly line, or engine module line.
- Area or site: a building, program-focused hall, or entire plant.
ISO 22400 allows KPIs to be defined at any of these levels but does not specify which level a given role must use. In practice:
- Cell leads may need work-unit-level availability and short-interval control metrics.
- Program managers may prefer line- or area-level schedule adherence and capacity utilization.
- Executive leadership often uses site-level productivity, on-time delivery, and quality indicators.
Your reporting design decisions—what detail to expose to whom—are outside the standard’s scope, even though it underpins the metrics themselves.
Choosing time buckets and aggregation rules
ISO 22400 is explicit about time-related behavior (e.g., whether a KPI is point-in-time, shift-based, or period-aggregated), but it doesn’t tell you which time buckets to use for managing your aerospace plant. You decide whether to aggregate by shift, day, week, or program milestone, and how to roll up across shifts that span calendar days.
Similarly, the standard does not prescribe how to aggregate across heterogeneous resources. For instance, combining utilization for a bank of test stands with different capabilities and maintenance regimes is a modeling choice. You might weight by criticality, capacity, or program relevance; ISO 22400 simply ensures that the underlying utilization concept is consistently defined before aggregation.
Combining ISO 22400 with Domain-Specific Metrics
Aerospace manufacturers cannot operate solely on generic production metrics. They need KPIs that reflect traceability, configuration control, and safety-critical quality performance. ISO 22400 is designed to coexist with these domain-specific metrics rather than replace them.
Aerospace traceability and MRO turnaround KPIs
Traceability metrics are central in aerospace but not explicitly modeled in ISO 22400. Examples include:
- Coverage of part genealogy data for serialized components and assemblies.
- Time to achieve full digital sign-off across all required operations on a work order.
- Percentage of parts with complete material, process, and inspection provenance attached to the digital thread.
Connect decisions to execution
Connect981 helps turn this kind of operational detail into traceable action, so the context behind each decision does not get lost.
For MRO operations, turnaround-time KPIs may break down total elapsed time into waiting-for-parts, waiting-for-engineering, teardown, inspection, repair, test, and paperwork segments. These draw on ISO 22400 time-structure ideas but are tuned to MRO realities and contract penalties.
In both cases, ISO 22400 provides reusable building blocks such as order states and time categories, while specialized KPIs capture the aerospace-specific concerns.
Energy, sustainability, and ESG-related metrics
Space and defense programs increasingly track energy use, emissions, and resource efficiency, whether for internal commitments or customer reporting. ISO 22400 includes generic energy-related indicators, but it does not define a complete ESG reporting model. You may need to extend your KPI framework to cover:
- Energy per test hour on thermal vacuum chambers or engine test stands.
- Scrap and rework rates expressed as material mass or embodied carbon per flight-critical assembly.
- Resource utilization for specialized, high-energy processes such as large autoclave cycles.
These metrics often combine ISO 22400 production indicators with sustainability data in your data warehouse. The standard remains a definitional anchor, not the full solution.
Using ISO 22400 as a Foundation for Custom KPI Frameworks
The most effective use of ISO 22400 in aerospace manufacturing is as a stable foundation for a tailored KPI framework rather than as the framework itself. This involves careful use of standardized terminology and transparent documentation of what is, and is not, ISO 22400-aligned.
Building on standardized terminology
When designing KPI catalogs for an aerospace plant or multi-site network, using ISO 22400 terms where possible reduces ambiguity. For example:
- Base equipment utilization, availability, and performance KPIs on ISO 22400 definitions for time states and operating time.
- Align order-related KPIs with the standard’s view of planned vs. actual time structures for production orders.
- Reuse standard attributes (units of measure, trend direction, applicability) in KPI specifications.
On top of these, define aerospace-specific KPIs such as "nonconformances per 1,000 flight-critical operations," "digital work instruction adherence," or "configuration change adoption lag." These draw from ISO 22400 concepts but extend them to cover your AS9100 and program needs.
Documenting what is and is not ISO 22400-aligned
As the KPI set grows, it becomes important—especially in a connected ecosystem of OEMs and suppliers—to distinguish between metrics that directly follow ISO 22400 and those that are custom. Practical steps include:
- Tag each KPI in your catalog with an attribute that indicates whether it is fully, partially, or not aligned with ISO 22400.
- Provide traceability from custom KPIs back to the underlying standard concepts they reuse (e.g., based on ISO 22400 equipment busy time).
- Clarify definitions in data dictionaries and interface specifications so that suppliers and partners know which metrics can be interpreted via the standard.
Platforms like Connect981 can help enforce this discipline: the data model can encode ISO 22400 semantics for core KPIs while allowing program-specific measures to coexist, clearly labeled as extensions. This approach maintains comparability where it matters—such as equipment effectiveness across multiple plants—without constraining the nuanced performance views required by aerospace engineering and quality teams.
Implications for Digital Manufacturing Infrastructure
In a modern aerospace production environment, ISO 22400 acts as a semantic layer across MES, ERP, PLM, QMS, historian, and analytics systems. It standardizes the language, but the architecture and workflows are designed by you.
When building or evolving a digital manufacturing infrastructure, understanding ISO 22400’s limits helps avoid two risks: expecting the standard to answer strategic questions it was never meant to address, and designing bespoke KPI definitions where standard ones already exist.
By treating ISO 22400 as a foundational reference, aerospace organizations can integrate heterogeneous systems, maintain consistent KPI semantics across a global supply chain, and still exercise full control over strategy, KPI selection, targets, and improvement practices.
Frequently asked questions
No. ISO 22400 does not define one universal, mandatory OEE formula that every plant must use.
What ISO 22400 actually standardizes
ISO 22400 (Manufacturing operations management – Key performance indicators) focuses on:
In practice, this connects to operational visibility when teams need to turn the answer into repeatable execution habits.
- Common terminology for KPIs such as availability, performance, quality, and OEE.
- Reference models showing how these components can be constructed.
- Example formulas and calculation approaches.
It provides a framework and examples, not a single, prescriptive OEE formula that overrides industry or site practice.
OEE within ISO 22400
Within that framework, OEE is typically treated as a composite metric based on:
- Availability (e.g., operating time vs. planned production time)
- Performance (e.g., actual output vs. theoretical maximum at standard rate)
- Quality (e.g., good units vs. total units produced)
ISO 22400 lays out structured ways to define and calculate these components and how they can be combined into higher-level indicators such as OEE, but the exact border definitions (what is counted as loss, what is “planned” vs. “unplanned,” how to treat changeovers, minor stops, start-up scrap, rework, etc.) are left to the implementing organization.
Implications for regulated, brownfield environments
For aerospace, defense, or other regulated plants with long-lived assets and mixed system landscapes:
- No automatic compliance: Using an OEE formula aligned with ISO 22400 terminology does not create or prove compliance with any regulation or standard.
- Site-specific definitions are required: You still need to define, in your own documentation, exactly how OEE is calculated for each line, cell, or asset class.
- Coexistence with legacy KPIs: Many plants already run MES, historian, or custom reporting with a legacy OEE variant. Replacing that overnight with an ISO 22400-style model is rarely realistic due to validation, downtime, and change-management burden.
- Change control and validation: Any shift toward an ISO 22400-aligned OEE structure should go through normal change control, including impact assessment on existing dashboards, contracts, capacity models, and potentially qualification/validation of calculations where they feed critical decisions.
Practical approach to using ISO 22400 for OEE
In practice, most regulated manufacturers use ISO 22400 as a reference rather than a strict recipe:
- Map your current OEE to ISO 22400 concepts (availability, performance, quality) so terminology is clear and comparable.
- Standardize definitions within the plant or network (e.g., consistent rules for planned vs. unplanned downtime, treatment of NPT, rework, and partial batches).
- Document the exact formula you use, including data sources, time filters, and handling of exceptions.
- Align systems gradually: When upgrading MES, historians, or analytics, align new implementations more closely with ISO 22400 while keeping backward compatibility and clear versioning of KPIs.
The key point: ISO 22400 gives you a structured language and examples for OEE, but you must still choose, document, and control your specific OEE formula for your environment.
AS9100 is owned and maintained by the International Aerospace Quality Group (IAQG), not by individual certification bodies or software vendors.
Who develops and controls AS9100?
The core ownership and maintenance of AS9100 sit with:
In practice, this connects to AS9100 compliance when teams need to turn the answer into repeatable execution habits.
- IAQG (International Aerospace Quality Group): An industry group made up of major aerospace OEMs and suppliers. IAQG develops the aerospace quality management system requirements that become AS9100.
- Sector organizations under IAQG: For example, AAQG (Americas), EAQG (Europe), and APAQG (Asia-Pacific) contribute to the content and balloting.
IAQG controls the technical content, revisions, and official guidance documents (such as clarifications and deployment support materials).
Who actually publishes AS9100?
Although IAQG owns the content, the standard is formally published by accredited standards bodies under license from IAQG, most prominently:
- SAE International (often designated as AS9100, e.g., AS9100D)
- ASD-STAN in Europe (EN 9100)
- Other national bodies that adopt the EN 9100 text as a national standard (e.g., BS EN 9100, DIN EN 9100).
The content is aligned with ISO 9001 plus additional aviation, space, and defense requirements, but ISO itself does not own AS9100.
What is the role of certification bodies?
Accredited certification bodies (CBs):
- Use the current AS9100 text owned by IAQG and published by SAE/ASD-STAN.
- Are overseen by accreditation bodies that participate in the ICOP (Industry Controlled Other Party) scheme under IAQG.
- Have no authority to change AS9100 requirements; they interpret and apply them within IAQG and accreditation rules.
In regulated, long-lifecycle environments, relying on a single CB or software vendor for interpretation without checking IAQG and sector guidance can create divergence from the actual standard over time.
What does this mean for manufacturers and MROs?
For plants operating in brownfield, mixed-system environments:
- Source of truth: The authoritative technical content is the current AS9100 edition as published by SAE/ASD-STAN, driven by IAQG. Local procedures, MES/QMS configurations, and training should trace back to this source.
- Change impact: When IAQG issues a new revision or clarification, you are responsible for assessing the impact across legacy systems (QMS, MES, ERP, PLM) and processes. There is no automatic grandfathering of old interpretations.
- Traceability: For audit readiness, be explicit about which AS9100 revision you are aligned to and keep controlled copies of the official text and any IAQG sector guidance used in your interpretations.
Owning these links yourself is important because standards revisions occur on timelines that rarely match major system upgrade cycles, and full system replacement simply to track an AS9100 update is usually not practical or economical in aerospace-grade environments.
Making ISO 22400 KPI calculations auditable is less about the standard itself and more about how you define, implement, and govern the KPI logic in your systems. In regulated, brownfield plants, auditable KPIs require unambiguous definitions, reliable data capture, controlled calculation logic, and reproducible results backed by evidence.
1. Start with precise, written KPI definitions
ISO 22400 describes concepts and reference calculations, but each plant still makes choices. To be auditable, you should maintain a KPI definition sheet for each KPI that includes at least:
In practice, this connects to ISO 22400 KPI governance when teams need to turn the answer into repeatable execution habits.
- Name and identifier (e.g., ISO22400_OEE_V1, ISO22400_Availability_V2).
- Scope: line, machine group, shift, product family, plant; plus time horizon (shift, day, week).
- Exact formula, including units and references to the specific ISO 22400 clause or figure where applicable.
- Time base definitions: what counts as planned time, operating time, planned/unplanned downtime, and which status codes map to each bucket.
- Included and excluded events: e.g., warmup, maintenance, testing, changeovers, engineering trials, rework.
- Data fields used: system, table, tag, or signal names (from MES, historian, PLC, ERP, QMS, etc.).
- Aggregation rules: how you roll up across shifts, machines, or orders (e.g., weighted by planned time or output quantity).
- Known limitations and assumptions: for example, how you handle missing machine states, partial cycles, or backfilled production counts.
Auditors will challenge anything that is ambiguous or inconsistently applied across lines or plants. Written definitions are the baseline for repeatability.
2. Make data lineage from KPI to raw signals traceable
To be auditable, anyone should be able to start from a reported KPI value and trace back to:
- The underlying time series of machine states and production counts.
- The work orders, part numbers, and shift calendars involved.
- The exact calculation logic and version that produced the result.
Practical steps:
- Retain time-stamped raw data from MES, SCADA/PLC, historian, and ERP at a resolution that supports reconstruction of events (for many KPIs, 1-second to 1-minute resolution is typical).
- Maintain a data dictionary that maps source tags and fields (e.g., PLC bits, MES state codes, ERP order status) to KPI categories such as operating time, minor stop, changeover, scrap, or rework.
- Record data transformations (e.g., state code reclassification, time bucket merging, filtering of obvious noise or outliers) with versioned logic.
- Keep referential links between production events, work orders, batches, and KPIs (e.g., a KPI instance references specific order IDs and date ranges).
If your KPI platform cannot show how a value was derived from raw data, auditors will treat it as a dashboard number rather than as reliable evidence.
3. Put calculation logic under change control
Many plants implement ISO 22400 KPIs in multiple places: historian scripts, MES reports, BI tools, or custom SQL. This is a common source of non-auditable discrepancies.
To keep calculations auditable:
- Centralize KPI logic as much as possible in a single, validated layer (e.g., MES or an analytics engine) and treat that as the system of record.
- Apply formal change control to KPI definitions and logic: documented change requests, impact assessment, testing, approvals, and effective dates.
- Version all calculation code and configurations (SQL, ETL flows, scripts, BI measures) in a repository where you can reconstruct the exact logic used on any historical date.
- Document deviations from ISO 22400: if you implement a plant-specific variant of OEE or availability, label and document it as such rather than calling it “ISO 22400” without qualification.
In regulated environments, ad hoc dashboard logic without version control is a major audit risk, even if the formulas are mathematically correct.
4. Validate the full calculation pipeline
In aerospace, pharma, and other regulated sectors, KPI numbers are often used to support capacity decisions, improvement programs, and sometimes compliance evidence. That makes the calculation pipeline itself subject to validation expectations.
Consider a basic validation approach:
- Define intended use: for example, “shift-level ISO 22400 availability and OEE for internal performance management, not used directly for product release decisions.”
- Perform installation and operational checks: confirm data flows from each source (MES, historian, ERP) are complete, time-synchronized, and secure.
- Develop test cases: use controlled historical periods where states and counts are known (e.g., a planned training day with a known stop pattern) and verify that your pipeline reproduces the expected KPI values.
- Document limitations: for example, “Cycle counts on Line 3 prior to date X are underreported during minor stops due to PLC configuration; KPI values before that date are not fully comparable.”
If your organization is subject to formal CSV or software validation expectations, your KPI tooling and data integration stack may fall in scope. Work with quality and IT to set appropriate validation depth.
5. Ensure consistent handling of time, shifts, and calendars
ISO 22400 KPIs such as availability, utilization, and OEE depend heavily on how you define planned time and schedule exceptions. These details are common audit failure points.
- Use controlled calendars for shifts, holidays, and site-specific events, ideally managed in a master system (MES, HR, or scheduling tool) and propagated downstream.
- Define standard rules for how you treat early starts, overtime, partial shifts, and overlap between shifts.
- Classify schedule exceptions explicitly: e.g., planned maintenance, trials, and engineering work that should be removed from planned production time.
- Synchronize time zones and clocks across OT and IT systems so that event sequences remain reconstructable.
Auditable KPIs require that two analysts using the same rules and data can independently reproduce the same results for a given period.
6. Design reports for drill-down and reproducibility
Auditability also depends on practical usability. Reports and dashboards should support tracing a number back to its components.
- Make drill-down supported: from monthly OEE to daily, shift-level, machine-level, and event-level views.
- Show KPI components: for example, for OEE, separately display availability, performance, and quality, with their numerators and denominators.
- Display applied filters and versions: time range, scope, excluded events, and KPI definition version.
- Allow export of underlying event data for sampled periods to support manual recalculation and evidence reviews.
If an auditor cannot inspect how a KPI changed when they adjust time filters or drill down into a particular machine or order, they will question its reliability.
7. Manage coexistence with legacy MES, historians, and BI tools
Most plants already calculate some form of OEE or ISO 22400-like KPIs in multiple systems. Full replacement is rarely realistic due to validation burden and downtime risk. Instead:
- Pick one system as the KPI system of record for ISO 22400-aligned metrics, then document that all official numbers come from there.
- Map and reconcile existing metrics in legacy tools to the new definitions; document differences (e.g., “Old_OEE includes planned maintenance as downtime; ISO22400_OEE excludes it.”).
- Phase out non-comparable KPIs or clearly label them as legacy indicators to avoid mixing them with ISO 22400 KPIs in formal reports.
- Implement interface tests to ensure data extracted from MES/ERP/historian into the KPI engine matches the source (record counts, sums, sample spot-checks).
Auditability suffers when multiple conflicting KPI values exist for the same period without a clear explanation. Reconciliation and labeling are essential during transition.
8. Capture governance, ownership, and training
Even with robust technical controls, ISO 22400 KPI calculations will not be auditable unless people understand and follow the rules.
- Assign ownership for each KPI (typically operations or industrial engineering) with clear responsibilities for definition, review, and continuous improvement.
- Set a review cadence where KPI definitions, data quality, and observed anomalies are periodically checked and updated under change control.
- Train key users (engineers, supervisors, analysts) on the definitions, typical pitfalls (e.g., double-counting, misclassified downtime), and how to respond to audit questions.
- Maintain an evidence pack for each key KPI: definition documents, sample calculations, validation records, and recent change logs.
9. What auditors will typically look for
While specific expectations vary by regulator and customer, auditors reviewing ISO 22400-style KPIs used in decision-making commonly test:
- Can you explain the formula and link it to ISO 22400 where applicable?
- Can you trace a reported value back to raw data, with consistent time stamps and event records?
- Is the calculation logic controlled and versioned, with documented changes and approvals?
- Are there documented data quality controls and known limitations?
- Can two people independently recalculate and match a sample KPI period using the same data and rules?
If you can provide clear answers and evidence for these points, your ISO 22400 KPI calculations will generally be considered auditable, even in complex, mixed-vendor environments.