Maintenance of DoD's weapon systems and mission support assets (i.e., materiel maintenance) is a critical element in the readiness and sustainability of combat forces. The distribution of maintenance workloads among the public and private sectors is instrumental in maintaining a robust and viable industrial base. DoD's materiel maintenance operations in FY 2016 supported a wide range of weapon systems including approximately 440,000 ground combat and tactical vehicles, 14,000 aircraft/helicopters, 780 strategic missiles, and 225 ships.

DoD maintenance is accomplished by two different yet complementary components — depot-level and field-level maintenance activities. The two components are distinguished largely by their relative capabilities, flexibility, agility, and capacity.

Depot-level maintenance entails materiel maintenance requiring the major repair, overhaul, or complete rebuilding of weapon systems, end items, parts, assemblies, and subassemblies; manufacture of parts; technical assistance; and testing. Each military service manages and operates its own organic depot-level maintenance infrastructure. For FY 2016, DoD spent nearly $32 billion for depot-level maintenance and repair work. Approximately 55 percent of the Department's FY 2016 depot-level workload was accomplished in organic facilities; the remainder was done in the private sector — by commercial firms.

Field-level maintenance comprises shop-type work as well as on-equipment maintenance activities at maintenance levels other than depot. Intermediate or shop-type work includes: limited repair of commodity-oriented assemblies and end items (e.g., electronic “black boxes” and mechanical components); job shop, bay, and production line operations for special requirements; repair of subassemblies such as circuit boards; software maintenance; and fabrication or manufacture of repair parts, assemblies, and components. On-equipment or organizational maintenance is normally performed by an operating unit on a day-to-day basis to support operations of its assigned weapon systems and equipment. Organizational maintenance encompasses a number of categories, such as inspections, servicing, handling, preventive maintenance, and corrective maintenance. The total cost of field-level maintenance for FY 2016 was estimated to be $42 billion.

Nearly 610,000 maintainers (Active Duty and Reserve Component Military and DoD civilians) were involved in DoD maintenance operations in FY 2016. Of this total, approximately 8 percent were federal civilian employees assigned as depot-level maintenance personnel and 92 percent accomplish field-level maintenance activities. In addition, several thousand private sector firms are engaged in performing mostly depot-level maintenance of DoD material.

Note: This Web site serves as a repository for selected DoD maintenance information and data, which do not constitute official DoD correspondence. Included are policy documents, plans and reports, historical trends and projections, public and private sector workload information, and links to defense and contractor Web sites.