The paper aims at presenting the self-maintenance concept of the ship's systems. The self-maintenance systems are fault tolerant systems that, in case of failure detection, will perform the self-maintenance procedure and continue with normal operation. But the term maintenance does not refer here to the repair or manual replacement of the faulty part in the system. Self-maintenance includes getting back the failure detected system into normal function, thus increasing the functional redundancy of a system and, at the same time, reducing the maintenance costs. Two types of self-maintenance are analyzed in this paper: the controlling and functionally-redundant one. When the controlling type is in question, repairs are undertaken by adjusting different paramenters that have an impact on the ship's operation, while in the functionally- redundant one, the ship's system is returned into normal working condition by restructuring the system.