How does MTBF/MTTR influence maintenance stocking decisions?

• A. By predicting reliability and helping optimize maintenance intervals and stock levels.
• B. By determining crew scheduling.
• C. By setting MEL limits.
• D. By forecasting weather.

Answer: (A)

MTBF and MTTR provide a clear picture of how often a part will fail and how long repairs will take, and that directly drives stocking decisions. If failures are infrequent (high MTBF), you can keep leaner spare parts because the expected usage is low. If failures occur often (low MTBF), you need more spares to cover those failures and meet maintenance schedules. If repairs take a long time (high MTTR), downtime costs rise, so having on-hand critical spares—or faster access to them—becomes more important to keep operations running. When planning stock levels, you combine these reliability and downtime estimates with lead times and service targets to set safety stocks and reorder points. In short, MTBF/MTTR help forecast spare parts demand and downtime impact, guiding how much to stock and when to reorder.