Mean Time Between Failure

Mean Time Between Failures (MTBF) is a reliability metric for repairable equipment, calculated as total operating time divided by the number of failures over a measured period. It represents the average operating time between failures, helping industrial teams estimate how long assets like conveyors, forklifts, scanners, and storage automation can run before the next failure.

On a shop floor or in a warehouse, MTBF is used to rank asset reliability and schedule preventive maintenance before recurring failures interrupt production or material flow. For example, if a conveyor, pallet wrapper, AS/RS shuttle, or handheld RF scanner records three failures across 900 operating hours, the MTBF is 300 hours, meaning the asset averaged 300 run-hours between failures. In inventory and material tracking environments, MTBF helps maintenance and operations teams predict where repeated downtime is most likely to disrupt receiving, putaway, replenishment, kitting, or line-side material delivery. The metric is especially useful when comparing similar assets across shifts, lines, or warehouses because it normalizes failure frequency by runtime instead of calendar time. MTBF applies to repairable assets; for non-repairable items, MTTF is the more appropriate term.

• ⚠️Calendar time in the denominator: Counting idle hours as operating time inflates the denominator and makes reliability look better than reality, which can delay spare-parts stocking or maintenance intervention.
• ⚠️Every stoppage counted as failure: Logging operator pauses, planned maintenance, or blocked material flow as failures depresses MTBF and misleads maintenance planning, causing unnecessary work and wasted resources.
• ⚠️Mixing asset types: Applying MTBF to non-repairable components or combining component-level and system-level failures in one dataset creates invalid comparisons, leading to poor procurement and replacement decisions.