ISA-95 in Aerospace: Defining What ERP, MES, QMS, and PLM Should Own

Aerospace teams rarely fail audits because nobody collected data. They fail because nobody can prove which system owned the data, which revision was current, or which decision blocked release.

ISA-95, also known as ANSI/ISA-95 or IEC 62264, is an international standard for enterprise control system integration and for integrating enterprise office systems with factory floor control systems. In aerospace and MRO, isa 95 matters because AS9100, NADCAP, FAA, EASA, ITAR, CoCs, FAI packages, serial genealogy, and supplier evidence all depend on clean boundaries.

Connect 981 applies this boundary thinking as a unified operations layer between ERP, MES, PLM, QMS, suppliers, and the connected shopfloor.

Quick overview: ISA-95 levels and aerospace system roles

The ISA-95 model consists of five levels that describe the flow of information and activities within an organization, from the plant floor up to the enterprise level. ISA-95 defines a five-level model that describes the flow of information and activities within an organization, from the physical production processes at Level 0 to business planning and logistics at Level 4.

• Level 0 describes physical production processes, machinery, raw materials, and physical assets on the floor.
• Level 1 focuses on sensing and manipulating the production process through control devices, sensors, actuators, intelligent devices, and basic control functions.
• Level 2 involves monitoring and supervisory control using programmable logic controllers, distributed control systems, SCADA, batch control, control module logic, and industrial control systems.
• Level 3 is the manufacturing operations management level. It includes manufacturing execution systems, manufacturing execution systems mes, manufacturing operations management systems, manufacturing operations systems, quality control, maintenance activities, production scheduling, inventory control, and operational control.
• Level 4 covers business planning and logistics. This includes enterprise resource planning, enterprise resource planning erp, erp systems, logistics systems, business systems, enterprise systems, business operations, and business processes.

ISA-95 provides standard terminology and models to bridge the gap between information technology and operational technology. The common data model established by ISA-95 ensures consistent information exchange between enterprise and control systems. The framework is based on the Purdue Reference Model, also called the purdue enterprise reference architecture, with hierarchy models and a hierarchical structure for industrial automation.

What belongs in ERP at ISA‑95 Level 4

Level 4 owns the commercial plan, not the detailed build method. Enterprise resource planning ERP should own:

• Customer contracts, demand, shipsets, sales orders, project accounting, and earned value.
• Item master basics: part number, description, UOM, make/buy, cost category, high-level revision.
• Inventory management: on-hand stock, warehouse balances, batch or lot quantities.
• Purchase orders, approved supplier commercial records, delivery schedules, and raw materials commitments.
• High-level routings and work centers for capacity and costing, not operator instructions.

ERP decisions include MPS, MRP, material allocation, make-vs-buy, PO expedite logic, and release of production orders. ISA-95 Part 1 and Part 2 define object models, object model attributes, production capability, inventory, and schedule objects that support those decisions.

Avoid using ERP for torque readings, inspection signoffs, NC program tracking, NADCAP parameters, or quality gate enforcement. That creates static PDFs, duplicate entry, and weak traceability.

What belongs in MES / MOM at ISA‑95 Level 3

Level 3 turns plans into executable manufacturing activities. Manufacturing operations management covers production operations, quality operations, maintenance operations, and inventory operations through operations activity models and production segments.

MES, MOM, or Connect 981 should own:

• Detailed routing, operation sequence, dependencies, and station instructions.
• Digital work instructions tied to PLM drawings, models, and revision control.
• WIP status by serial, lot, tail number, station, operator, and timestamp.
• Data acquisition from tools, equipment, and manufacturing systems.
• Operator signatures, time-on-task, resource usage, and inspection evidence.
• Local dispatching based on tooling, skills, machine status, shortages, and holds.

In practice, MES is the execution truth for an engine MRO visit, a composite layup, a wing panel, or a heat treat load. It captures historical data, furnace curves, NDT results, serialized genealogy, and links to calibrated equipment.

MES should not own long-term forecasting, engineering authority, or final MRB policy.

What belongs in QMS: quality planning, records, and decisions

QMS spans Level 3 and Level 4. It defines quality policy, while execution systems capture evidence.

QMS should own:

• AS9100, NADCAP, FAA/EASA, ITAR, and customer procedure requirements.
• Inspection plans, control plans, sampling rules, acceptance criteria, and FAI requirements.
• Nonconformance, MRB, CAPA, concessions, deviations, escapes, and customer returns.
• Supplier approval, audit findings, calibration evidence, and supplier quality metrics.

AS9100 traceability requires documented identification, status, acceptance authority, and unique identification where required. QMS defines conforming versus nonconforming product. MES or Connect 981 presents the checks, captures measurements, blocks progression, and returns structured evidence.

Avoid scanned forms buried in ERP attachments. They slow audits and weaken regulatory compliance.

What belongs in PLM: product definition and engineering authority

PLM owns product definition outside the ISA-95 pyramid but tightly feeds it.

PLM should own:

• eBOM, design intent, tolerances, specifications, MBD, drawings, and 3D models.
• Configuration rules for aircraft, engines, structures, repair schemes, and modification kits.
• ECR, ECO, revision effectivity by serial number, block number, or tail number.
• Engineering requirements, verification, and validation data.

PLM decides how the part is designed and when a revision becomes effective. ERP consumes released commercial attributes. MES consumes released work content. QMS aligns inspection characteristics and special process rules. Connect 981 helps keep data flows synchronized so operators do not build from obsolete instructions.

Control level (ISA‑95 Levels 0–2): what stays on the machines

The isa 95 standard keeps the control level focused on physical processes and control processes. Level 0 of the ISA-95 model describes the physical production processes, including machinery and other assets in the field or on the floor. Level 1 focuses on sensing and manipulating the production process, which includes devices like sensors and actuators that collect data and affect production. Level 2 involves monitoring and supervising control, which refers to systems like programmable logic controllers and distributed control systems that manage physical processes.

Typical aerospace assets include CNC machines, CMMs, autoclaves, test cells, torque tools, shot peen machines, NDT stations, and automated riveting systems.

Control level systems own immediate safety, interlocks, recipes, NC code, PLC logic, and local cycle data. They should not own part revision, quality policy, supplier status, or full traceability chains. Critical results must flow upward through standardized data exchange.

Ownership by data type: who is the system of record?

• Product definition and design intent: PLM, read by ERP, MES, QMS.
• Item master and commercial attributes: ERP, referenced by other systems.
• Detailed routing and work instructions: MES or Connect 981, linked to PLM.
• Production orders: ERP owns order creation; MES owns execution status.
• WIP and operation completions: MES, summarized back to ERP.
• Quality plans and criteria: QMS, enforced in the execution layer.
• Inspection evidence: MES or Connect 981 captures it; QMS governs it.
• NCR, MRB, CAPA: QMS owns decisions; MES supplies context.
• Serial genealogy: MES or execution layer, with rollups to ERP and QMS.
• Equipment capability: CMMS/EAM, integrated with MES and QMS.
• Supplier approval: QMS owns qualification; ERP implements purchasing controls.

ISA-95 prevents redundant work and reduces costly custom integrations by clearly defining software system responsibilities.

Ownership by decision type: planning, execution, and quality calls

ISA-95 is also a decision model.

• Long-term capacity, site moves, and investment: ERP and program governance.
• Master scheduling and MRP: ERP at the enterprise level.
• Finite scheduling and short-interval control: Level 3 execution system.
• Work instruction content: PLM defines design intent; manufacturing engineering authors executable steps in MES or Connect 981.
• Rework, concessions, alternate methods: QMS and PLM define rules; execution applies them.
• Product acceptance and release: QMS owns release; ERP ships only after release.
• Supplier changes: QMS and supply chain governance decide; ERP enforces purchasing status.

Example: a new NADCAP rule changes a heat treat requirement. QMS updates the procedure, PLM confirms affected specs, Connect 981 updates instructions and blocks noncompliant work, and ERP reflects schedule impact.

Common overlaps, gaps, and failure modes in aerospace ISA‑95 implementations

Most failures are boundary failures.

Common overlaps:

• ERP and MES both owning routings.
• QMS and MES duplicating inspection results.
• PLM and QMS holding different inspection characteristics.

Common gaps:

• No real-time WIP view across plants and suppliers.
• Serial genealogy trapped in spreadsheets, HMIs, or PDFs.
• ECOs not propagated to work instructions or supplier packets.
• ERP showing “released” while MES has a quality hold.

Failure modes include missed FAI updates, wrong-revision builds, incomplete CoC links, inconsistent special process coverage, and MRO return-to-service delays. A clear isa 95 model reduces these risks.

How Connect 981 applies ISA‑95 to unify aerospace operations

Connect 981 is not a monolithic ERP or MES replacement. It is an aerospace operations platform that uses isa 95 principles for seamless integration across ERP, PLM, QMS, suppliers, and shopfloor systems.

It supports:

• Level 3 execution: digital work instructions, WIP tracking, serial traceability, operator guidance, and audit evidence.
• Enterprise and supplier workflows: PO collaboration, contract review, supplier visibility, and shared documentation.
• Better information exchange across complex systems without forcing replacement of existing manufacturing systems.

Properly implemented, ISA-95 eliminates data silos between IT and OT, reducing integration costs and enhancing data visibility. Reduced integration costs are achieved by eliminating the need for custom, expensive, point-to-point software code between different vendor systems.

Next steps: applying ISA‑95 boundaries in your aerospace plant

ISA-95 is an international set of standards aimed at integrating logistics systems with manufacturing control systems, facilitating communication among various manufacturing layers. The primary goal of ISA-95 is to ensure that different systems and software can communicate effectively, enabling real-time visibility into production, assets, and workforce activity, which is crucial for scaling operations consistently across plants and regions.

More than 90% of manufacturers use ISA-95 to improve automation, ensuring that different systems and software can communicate effectively, which is crucial for real-time visibility into production and workforce activity. ISA-95 is widely used in modern manufacturing, with over 90% of manufacturers adopting it to improve automation and ensure that different systems and software can communicate effectively, which is crucial for Industry 4.0 initiatives.

Use this action plan:

• Map current systems to ISA-95 Levels 0 through 4.
• Assign each data type and decision type to one system of record.
• Identify overlaps that create rework, delays, audit exposure, or custom code.
• Pilot Connect 981 on one value stream, such as a nacelle line or engine MRO program.

Real-time shop floor visibility reduces safety stock and raw material waste, optimizing inventory management. Implementing ISA-95 can help manufacturers navigate evolving regulatory expectations and drive better business outcomes, including improved efficiency and reduced operational costs. ISA-95 enhances scalability by allowing for the addition of new production lines or software modules without disrupting the existing architecture.

Challenges in implementing ISA-95 often include legacy infrastructure complexity, data cleansing and classification issues, and the need for workforce training and change management to ensure successful deployment. Standardizing data exchange is key to ensuring that critical information flows between business systems and plant operations.

The ISA-95 standards framework is designed to facilitate the integration of logistics systems with manufacturing control systems, which is essential for the implementation of Industry 4.0 and the Internet of Things. ISA-95 provides a tech-agnostic communication model that remains relevant in the era of Industry 4.0, allowing global manufacturers to define, develop, and integrate complex systems and processes effectively.

To map your ERP, MES, QMS, PLM, and supplier landscape to practical desired outcomes, request a demo of Connect 981 or ask for an ISA-95 boundary workshop.