A 2025 Oliver Wyman survey of MRO executives measured how much inventory aviation maintenance companies hold to offset long lead times, and the results are shown in two doughnut charts. The survey drew 172 aviation professionals from airline and independent MROs, operators and original equipment manufacturers.

In the first chart, 17 percent of respondents said inventory at their company or customers rose by more than 15 percent. Another 52 percent reported an increase of 5 to 15 percent. Together those two groups account for 69 percent of respondents. Twenty-two percent said inventory stayed about the same, and 9 percent reported a decrease.

The second chart covers expectations if the supply chain becomes more reliable. Fifty-five percent expect inventory levels to decrease slightly, 32 percent expect them to remain at current levels, and 13 percent expect a substantial decrease.

Oliver Wyman reported little difference between operators and MRO or OEM respondents on inventory growth. The firm described holding more inventory as the fastest and most effective response to supply chain problems, and noted that the approach strains the manufacturing supply chain and adds to piece part shortages that lengthen turnaround times.

The survey placed the global MRO market at more than US$114 billion in 2024, with spending forecast at US$120 billion for 2025. The 2026 edition of the survey reports that market spend exceeded US$136 billion in 2025, and that the share of respondents expecting supply chain recovery within three years fell from 80 percent in 2024 to 70 percent in 2025 and 60 percent in 2026.

Source: Oliver Wyman - https://www.oliverwyman.com/our-expertise/insights/2025/apr/mro-industry-sees-growth-amid-supply-and-labor-pressure.html