Full definition
Major equipment revision including complete disassembly, individual component inspection, cleaning, repair or replacement of worn parts and reassembly to original or improved (as-new) condition. Typical interval: 20,000-60,000 operating hours, or every 3-5 years per manufacturer. Preceded by detailed planning: scope, parts, tools, personnel and schedule. Executed during planned shutdown. Documented with inspection report and recommendations for the next cycle. Unlike corrective maintenance: planned and systematic.