Who approves a Planned Maintenance System and on what basis is the maintenance carried out?

flowchart LR
    A[Classification Society] -->|approves| B[PMS per UR Z20]
    B --> C[Maintenance basis]
    C --> D[Manufacturer recommendations]
    C --> E[Running hours]
    C --> F[Calendar intervals]
    C --> G[Condition monitoring]
    C --> H[Operator experience]

• Approval authority: Classification society (IACS Member) under IACS UR Z20
• Basis of maintenance: manufacturer’s recommendations, running hours, calendar intervals, condition monitoring, documented operator experience
• SMS framework: ISM Code section 10 requires planned, procedure-driven, recorded maintenance
• Indian application: MS Act 2025 s.147 applies ISM Code to Indian ships
• Chief Engineer role: responsible on board for PMS, signs overhaul documentation, ensures maintenance per approved scheme