The Ships' Maintenance and Material Management (3-M) Manual, OPNAVINST 4790.4, describes in detail the Ships' 3-M Systems. The

primary objective of the Ships' 3-M Systems is to provide for managing maintenance and maintenance support in a way to ensure maximum equipment operational readiness. The Ships' 3-M Systems is divided into two subsystems. They are the planned maintenance system (PMS) and the maintenance data system (MDS).

PURPOSES OF PMS

The PMS was established for the following purposes:

To reduce complex maintenance to simplified procedures that are easily identified and managed at all levels

To define the minimum planned maintenance required to schedule and control PMS performances

To describe the methods and tools to be used

To provide for the detection and prevention of impending casualties

To forecast and plan personnel and material requirements

To plan and schedule maintenance tasks

To estimate and evaluate material readiness

To detect areas requiring additional or improved personnel training and/or improved maintenance techniques or attention

To provide increased readiness of the ship

BENEFITS OF PMS

The PMS is a tool of command. By using PMS, the commanding officer can readily determine whether the ship is being properly maintained. Reliability and availability are improved. Preventive maintenance reduces the need for major corrective maintenance, increases economy, and saves the cost of repairs.

The PMS assures better records because the shipboard maintenance manager has more useful data. The flexibility of the system allows for programming of inevitable changes in employment schedules. This helps to better plan preventive maintenance.

The PMS helps leadership and management reduce frustrating breakdowns and irregular hours of work, and thus improves morale. It enhances the effectiveness of all hands.

LIMITATIONS OF PMS

The PMS is not self-starting; it does not automatically produce good results. It requires considerable professional guidance and continuous direction at each level of the system's operation. One individual must have both the authority and the responsibility at each level of the system's operation.

Training in the maintenance steps as well as in the system is necessary. No system is a substitute for the actual technical ability required of the petty officers who direct and perform the upkeep of the equipment. Because of rapid changes in the Ships' 3-M Systems, always refer to a current copy of the 3-M Manual.