Aircraft carriers are very complex systems. The USN aircraft carriers are required to balance three goals. This RAND study looks at how those goals can be traded-off.
Cycles and Operational Availability
Given a fixed number of months for maintenance, deployments, and time between deployments (consistent with personnel quality-of-life goals), Navy planners face a three-sided trade-off in setting ship schedules. They must balance goals of
- deploying carriers and generating forward presence
- holding a carrier in reserve and keeping it surge-ready to meet emerging needs
- maintaining the materiel condition of the ship.
This is a zero-sum trade-off in which improving the ability to meet one goal can adversely affect the ability to meet the others.
Under the current 32-month, one-deployment cycle, for example, in which both the deployment and maintenance periods typically last six months, a carrier is deployed 19 percent of the time, able to surge within 30 days 46 percent of the time and within 30-90 days an additional 11 percent of the time, and in depot maintenance 24 percent of the time. A shorter, 18-month cycle would see a carrier deployed 31 percent of the time, able to surge within 30 days 15 percent of the time and within 30-90 days 18 percent of the time, and in depot maintenance 36 percent of the time.
A longer, 42-month cycle featuring two 6-month deployments would see a carrier deployed 29 percent of the time, able to surge within 30 days 44 percent of the time and within 30-90 days 9 percent of the time, and in maintenance 18 percent of the time. A longer cycle would help meet the 6+1 fleet goal of having at least six carriers deployed or able to deploy within 30 days and an additional one able to deploy in 90 days. It is not clear, however, whether required depot maintenance can be completed in one 6-month period every three and a half years
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On balance, our analysis suggests that shortening the one-deployment cycle will increase the forward presence of the carrier fleet but reduce its ability to meet the 6+1 fleet goal. Shorter cycles can also help level workload at the shipyards. Longer, two-deployment cycles will increase forward presence while sustaining higher levels of readiness for longer periods of time only if the workload management challenges they raise are addressed. As noted, the Navy needs to perform engineering studies to examine the impact of increased maintenance demands in two-deployment cycles. Table 1 summarizes the advantages and disadvantages of each notional cycle mentioned above over the current 32-month cycle.
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