# What Is a Planned Maintenance System (PMS) on Ships? | Faromo

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Language: en

Learn how ship PMS works, including calendar and running-hour maintenance, work orders, equipment trees and audit records.

Modified: 2026-08-16

Reviewed: 2026-08-16

A PMS is the technical management system used to plan, execute and document vessel maintenance and calculate the next due point.

An effective PMS links every maintenance task to specific equipment, instructions, interval and responsible role. Completion updates equipment history and calculates the next due point.

Calendar tasks recur by days or months, while running-hour tasks depend on equipment use. For many critical jobs, maintenance becomes due when the first of the two thresholds is reached.

## Equipment hierarchy

Organizes technical structure and maintenance history from main system to sub-equipment.

## Maintenance job library

Standardizes instruction, interval, owner, required spares and safety information.

## Due calculation

Creates work by calendar, running hours or whichever threshold comes first.

## Work order

Turns the planned job into an executable record for a date, team and vessel.

## Postponement and approval

Preserves decision and date history for justified postponements.

## Audit history

Links completion result, readings and evidence files to equipment.

## Workflow

1. Define equipment: Create the technical tree and critical-equipment scope.
2. Plan the job: Define interval, instruction, owner and spare requirements.
3. Execute the work order: The team records result, readings and materials used.
4. Preserve history: The result closes and the next maintenance point is created.

## Are PMS and CMMS the same?

They share similar maintenance principles. In shipping, PMS commonly refers to the planned maintenance system used in vessel, class and ISM context.

## Which maintenance is planned by running hours?

Main engines, generators, pumps and similar operating equipment may use counter-based intervals according to manufacturer instructions.

## How should overdue maintenance be managed?

Delay should be visible, with risk, reason, revised plan and authorized approval recorded. Critical requirements must be verified against company and class procedures.

## What should you look for in a PMS?

Evaluate equipment hierarchy, calendar and counter rules, work orders, postponement, spare linkage, offline operation and audit trail together.

## Sources

- [International Safety Management (ISM) Code](https://www.imo.org/en/ourwork/humanelement/pages/ismcode.aspx)
- [International Convention for the Safety of Life at Sea (SOLAS)](https://www.imo.org/en/about/conventions/pages/international-convention-for-the-safety-of-life-at-sea-(solas),-1974.aspx)