What are the two levels of maintenance in the military supply system?

The two levels of maintenance in the military supply system are indeed field and sustainment. Field maintenance primarily occurs at the unit level, where personnel are responsible for routine tasks such as repairs and minor overhauls necessary to keep equipment operational in the short term. This level of maintenance is crucial for ensuring that forces can quickly react to immediate operational needs and maintain equipment readiness during training or in combat situations.

Sustainment maintenance, on the other hand, occurs away from forward operating areas and involves more extensive repairs and overhauls that require specialized facilities and equipment. This level is essential for maintaining long-term equipment viability, ensuring that larger systems or weaponry can continue to function effectively throughout their lifecycle. It focuses on the broader logistics and supply chain support required to sustain military operations over time.

This distinction between field and sustainment maintenance emphasizes the operational readiness at the tactical level and the logistical support necessary for long-term strategic effectiveness, highlighting different aspects of maintenance in the military supply chain.