Major Overhaul
A major overhaul is an extensive planned restoration in which equipment is disassembled, inspected, repaired, renewed, tested, and returned to a defined performance standard.
What this term means in maintenance
A major overhaul is an extensive planned restoration in which equipment is disassembled, inspected, repaired, renewed, tested, and returned to a defined performance standard.
What a major overhaul may include
An overhaul can involve:
- Full disassembly
- Cleaning
- Dimensional inspection
- Nondestructive testing
- Replacement of wear components
- Machining
- Balancing
- Alignment
- Reassembly
- Performance testing
- Documentation
Practical example
A compressor is removed during a turnaround, dismantled, inspected, fitted with renewed bearings and seals, balanced, reassembled, aligned, and load-tested.
Planning requirements
The work should define:
- Scope
- Inspection criteria
- Replace-versus-reuse limits
- Parts and long-lead items
- Specialist vendors
- Tolerances
- Hold points
- Test requirements
- Warranty
- Documentation
Overhaul decision
The decision should consider condition, reliability, cost, replacement options, obsolescence, and remaining business need.
Common mistake
Beginning disassembly without clear inspection criteria and parts readiness can create long delay and uncontrolled scope growth.
Related concepts
Related maintenance terms
Keep exploring connected CMMS, reliability, and maintenance planning terms.
Turnaround Maintenance
Turnaround maintenance is a large, planned facility or process outage used to complete major inspection, repair, replacement, modification, and compliance work.
Asset Lifecycle Management
Asset lifecycle management is the coordinated management of an asset from need and acquisition through operation, maintenance, improvement, renewal, and disposal.
Maintenance Job Plan
A maintenance job plan is a reusable definition of the labor, steps, parts, tools, safety controls, references, and completion requirements for a maintenance task.
Glossary FAQs
- What is a major overhaul?
Extensive disassembly, inspection, restoration, reassembly, and testing of equipment.
- What should be defined before disassembly?
Scope, inspection criteria, tolerances, parts, hold points, and test requirements.
- How is overhaul different from replacement?
Overhaul restores existing equipment, while replacement introduces another asset or unit.