# What Is a PMS (Planned Maintenance System)? — Definition
A Planned Maintenance System (PMS) is software used on board and in shore offices to plan a vessel’s maintenance. It schedules, tracks and records all planned maintenance work. This supports compliance with the ISM Code and classification society rules.

URL: https://navatom.com/glossary/planned-maintenance-system

## Synonyms
- PMS
- Planned Maintenance System

## Definition
A Planned Maintenance System (PMS) is a specialized software platform used aboard ships and within shore-based offices to schedule, track, and document all planned maintenance activities on a vessel. At its core, a PMS ensures that every piece of critical equipment — from main engines and generators to navigation systems and life-saving appliances — receives maintenance at the intervals prescribed by the manufacturer, the classification society, and international regulations such as the ISM Code.
## Why a PMS Matters
The ISM Code requires every ship management company to maintain a documented Safety Management System (SMS), and maintenance planning is a central pillar of that system. Classification societies such as DNV, Lloyd’s Register, and Bureau Veritas mandate that vessels demonstrate continuous compliance with structural and mechanical standards.
Without a PMS, managing the hundreds of recurring maintenance jobs across a fleet becomes chaotic, leading to overdue tasks, failed audits, and potential detentions by port state control inspectors.
## Key Components of a PMS
A modern PMS typically includes job scheduling with calendar-based and running-hour-based triggers, work order management for assigning and tracking tasks, spare parts inventory tracking linked to each piece of equipment, and a full maintenance history log. The equipment hierarchy organizes every component on the vessel in a tree structure, making it straightforward for engineers to locate jobs and record completions.
Many systems also integrate condition monitoring data, allowing operators to shift from purely time-based maintenance to a condition-based approach.
## PMS vs. General CMMS
While a general Computerized Maintenance Management System (CMMS) handles maintenance for any industrial environment, a maritime PMS is purpose-built for the unique challenges of vessel operations. It accounts for limited connectivity at sea with offline synchronization, integrates with class survey schedules, supports ISM-compliant reporting, and structures data around vessel-specific equipment hierarchies.
Modern cloud-based PMS platforms synchronize data in real time between ship and shore, giving fleet managers full visibility into maintenance status across every vessel without waiting for email reports or manual uploads.

## Related Terms
- [Maritime CMMS](https://navatom.com/glossary/maritime-cmms) — A maritime CMMS (Computerized Maintenance Management System) is software that organizes, schedules and tracks the maintenance of shipboard equipment. Maritime versions add features for offline work, class surveys and ISM Code compliance.
- [Class Survey](https://navatom.com/glossary/class-survey) — Class surveys are regular inspections by classification societies. They check that a vessel still meets the structural, mechanical, electrical and safety standards of its class notation.
- [Ship Management Software](https://navatom.com/glossary/ship-management-software) — Ship management software is a digital platform that manages all aspects of vessel operations from one central system. It covers technical management, crew administration, procurement, safety and compliance, document control and operational reporting.