# Corrective maintenance

Corrective maintenance is, in WHO's Medical equipment maintenance programme overview (2011), a process used to restore the physical integrity, safety and/or performance of a device after a failure; WHO treats corrective maintenance, unscheduled maintenance and repair as equivalent terms.

WHO divides medical equipment maintenance into two categories: inspection and preventive maintenance, which includes all scheduled activities that ensure functionality and prevent breakdowns, and corrective maintenance, which restores the function of a failed device and allows it to be put back into service. For PSA oxygen plants, PATH and CHAI (July 2021) note that corrective maintenance may require rebuilding a valve assembly or compressor after a failure. WHO's technical specifications for oxygen generator plants (December 2024) ask for user training that covers the troubleshooting approach and corrective maintenance procedures and work instructions, where users can carry them out.

UNDP's REQ-OXY-001 (effective 1 January 2025) says that, if a service level agreement exists with the supplier, it should outline corrective maintenance terms, including estimated response times, lead times for spare parts, stockpile locations, remote support and the availability of local agents, and that maintenance services must include a warranty of at least two years covering preventive and corrective maintenance. [UltraCare](https://library.ultracontrolo.com/answers/what-is-ultracare/), the Ultra Controlo technical support programme, covers preventive maintenance, corrective service, original spare parts and emergency support. See [preventive maintenance](https://library.ultracontrolo.com/glossary/preventive-maintenance/).

## Sources

- [WHO, Medical equipment maintenance programme overview (WHO Medical device technical series, 2011), executive summary, introduction and definitions](https://iris.who.int/server/api/core/bitstreams/e5a3afa2-3eb0-41a0-820f-edb2032c41bb/content)
- [PATH and CHAI, Oxygen Generation and Storage: Pressure/Vacuum Swing Adsorption Plant (July 2021)](https://media.path.org/documents/O2_generation_and_storage_PSA_VSA_v1.pdf)
- [WHO, Technical specifications for health facility based medical oxygen systems (31 December 2024), oxygen generator plant table, line 38](https://iris.who.int/server/api/core/bitstreams/ff437601-add3-44c8-8149-b85f0cdb2b52/content)
- [UNDP, REQ-OXY-001 v01 (effective 1 January 2025), section 6.5](https://healthimplementation.undp.org/wp-content/uploads/2025/01/REQ-OXY-001-v01-UNDP-TECHNICAL-REGULATORY-REQUIREMENTS-FOR-OXYGEN-PLANTS.pdf)
- Ultra Controlo, Industrial 2026 catalogue, p. 22 (UltraCare)

Reviewed: 2026-10-23. Ultra Controlo engineering. https://library.ultracontrolo.com/glossary/corrective-maintenance/