Every factory, plant and airline depends on parts and materials that never appear in a finished product but keep operations running. This is MRO inventory. From ensuring the airworthiness of aircraft to maintaining safety standards, MRO inventory plays a pivotal role in every asset-heavy industry. Understanding "what is MRO" and leveraging advanced MRO inventory management solutions are essential for operational excellence. This article explores what MRO inventory means in industry and aviation, practical MRO inventory examples, how to manage and optimise it, and the role of MRO suppliers.
What is MRO inventory?
MRO inventory is the stock of items a business uses to maintain, repair and run its facilities and equipment, rather than items that become part of a finished product. The acronym has two common meanings:
- In manufacturing and most industries: maintenance, repair and operations (sometimes "operating") supplies, such as spare parts, tools, lubricants, safety gear and cleaning materials.
- In aviation: maintenance, repair and overhaul, the work and parts that keep aircraft airworthy.
In both cases, MRO inventory is usually treated as indirect spend, yet running out of a critical spare can stop a production line or ground an aircraft.
MRO inventory examples
Typical MRO inventory in manufacturing and industrial operations includes:
| Category | Examples | Why it matters |
| Spare parts | Bearings, motors, pumps, belts, valves | Prevent unplanned downtime |
| Consumables | Lubricants, filters, adhesives, welding supplies | Used daily; frequent reorders |
| Tools and equipment | Hand and power tools, gauges, calibration kits | Support safe, accurate repairs |
| Safety and facility supplies | PPE, fire extinguishers, cleaning materials | Protect people and compliance |
| Repairable parts | Gearboxes and motors sent for refurbishment | Lower cost than buying new |
In aviation, MRO inventory encompasses all materials, components, tools, and consumables essential for the maintenance and repair of aircraft. Unlike production materials or finished goods, MRO inventory focuses on ensuring operations run smoothly and regulatory compliance is maintained. Aviation MRO inventory examples include:
- Spare parts: Critical components like engines, landing gear, and avionics for scheduled maintenance or emergency repairs.
- Consumables: Items like lubricants, adhesives, and fasteners used during routine upkeep.
- Testing equipment: Diagnostic tools to monitor and maintain systems such as hydraulics and electronics.
- Safety equipment: Oxygen masks, life vests, and fire extinguishers for crew and passenger safety.
Given the complexities of aviation operations, robust MRO inventory management is a necessity.
The importance of MRO suppliers
Poor aviation MRO management can have costly consequences. Supply chain disruptions, such as delays or shortages, can derail maintenance schedules, and even a small oversight might lead to cancelled flights, operational losses, or, more critically, safety incidents. These issues affect operational efficiency, passenger schedules, and profitability, underscoring how vital MRO suppliers are in ensuring smooth operations.
Being the backbone of aviation, MRO suppliers must ensure safety, operational efficiency, compliance, and extended aircraft lifespan. Through tasks like inspections, maintenance, repairs, and overhauls, they keep aircraft flightworthy and cost-efficient for operators. By maintaining regulatory compliance and passenger safety, MRO suppliers keep fleets available and passengers safe.
Effective MRO supplier collaboration
The use of collaborative software is transforming procurement, driven by the need for enhanced visibility, efficiency, and responsiveness in a highly regulated and complex industry. Leveraging these platforms, MRO operations streamline communication and ensure real-time access to inventory data, reducing risks of overstocking or stock-outs.
Key benefits include integrating inventory systems with maintenance schedules, minimising aircraft downtime, and ensuring parts are available precisely when needed. Digital tools like cloud-based solutions and RFID technologies enhance tracking and automation, fostering seamless collaboration among suppliers, buyers, and operators. This integration addresses unpredictable demands and supply chain disruptions common in aviation.
Leading MRO suppliers specialise in categories like avionics, hydraulics, or structural components. Successful collaboration is essential, relying on strategies such as:
- Strategic partnerships: Long-term relationships for reliability.
- Vendor certification: Regulatory-compliant suppliers.
- Cost management: Negotiating terms to balance cost and quality.
As airlines increasingly rely on advanced technologies, the use of collaborative software in MRO inventory management not only meets regulatory requirements but also contributes to cost reduction and operational agility.
MRO inventory management best practices
MRO inventory management is the process of deciding which maintenance, repair and operations items to stock, how much to hold and where, and how to replenish them without tying up excess cash. These practices apply in both industrial and aviation settings:
- Classify items by criticality: rank parts by the impact of a stock-out (would it stop a line or ground an aircraft?) and by usage, so critical spares are always available and low-risk items are held lean.
- Clean up master data: remove duplicate part numbers, standardise descriptions and link items to the equipment they serve, so teams can find what is already in stock.
- Set min/max levels from real usage: base reorder points on consumption history and supplier lead times rather than guesswork.
- Control the storeroom: restrict access, record every issue and return, and run regular cycle counts to keep records accurate.
- Track the right KPIs: inventory turnover, stock-out rate, fill rate, carrying cost and the value of obsolete stock.
How to optimise and reduce MRO inventory
MRO inventory optimization means holding the minimum stock that still meets service levels. Common levers include:
- Identifying and disposing of obsolete and slow-moving items.
- Pooling common spares across sites instead of each site holding its own.
- Using vendor-managed inventory or consignment stock for high-volume consumables.
- Repairing rotable and repairable components rather than buying new, where safe and cost-effective.
- Forecasting demand from maintenance schedules and equipment condition data.
Technologies transforming MRO inventory management
Advanced MRO inventory management solutions are centred around leveraging cutting-edge technologies to enhance efficiency, reduce costs, and optimise aviation operations. These innovations not only enable MROs to maintain high standards of safety and reliability but also actively support sustainability goals, driving the aviation industry towards a more environmentally responsible future. Key features include:
- Smart equipment and IoT technology enable continuous performance tracking and maintenance forecasting, allowing airlines to address issues before they impact operations.
- Augmented reality (AR) is becoming a vital tool for technicians, overlaying diagrams and instructions directly onto machinery. This simplifies repair tasks and enhances training.
- Artificial intelligence (AI) analyses performance data to predict maintenance needs, optimise operations, minimise downtime, and enhance efficiency through proactive issue identification.
- Generative AI (GenAI): By acting as a "copilot," GenAI assists technicians with troubleshooting, improving supply chain processes, simplifying data-heavy tasks like managing technical manuals, boosting reliability, and enhancing operational efficiency.
- 3D printing: Additive manufacturing (3D printing) enables rapid, on-site production of aircraft components, minimising lead times, reducing reliance on traditional supply chains, and allowing for customised parts production.
- Sustainability initiatives focus on repairing parts over replacing them, conserving resources, reducing waste, and fostering efficient, data-driven MRO practices.
How can Infosys BPM help?
Infosys BPM supports aviation suppliers, OEMs and airlines with the digital and operational layer around physical maintenance: a digital control tower for real-time order and inventory visibility, master data enrichment integrated with ERP systems, robotic process automation (RPA) for quotes, part allocation and order reconciliation, and generative AI that predicts parts demand. For manufacturers, Infosys BPM’s sourcing and procurement teams also manage MRO category strategy and spend. Discover more about how Infosys BPM drives transformation in aviation MRO operations.
Frequently asked questions
MRO inventory is usually treated as an indirect cost because the items support operations rather than becoming part of a product. Consumables are generally expensed as they are used, while some high-value critical spares may be capitalised, depending on the accounting rules a company follows.
MRO category management is a procurement approach that groups maintenance, repair and operations spend into categories, such as bearings, electrical parts or safety supplies. Teams use spend analysis to consolidate suppliers, standardise items and negotiate better terms for each category.
There is no single figure. The right level depends on each item’s criticality, usage and supplier lead time. Most companies set minimum and maximum levels per item and review them regularly, holding critical spares even when usage is low.
A rotable part is an aircraft component that can be repaired or overhauled and returned to service many times, such as certain landing gear and avionics units. Rotables are tracked by serial number and often managed in shared pools to keep aircraft flying while parts are repaired.
