What is the meaning of MTBF when referring to rotating equipment?

MTBF, when referring to rotating equipment, stands for Mean Time Between Failures, which is a measure of the average time a piece of equipment is expected to operate without failure. It is a key indicator of equipment reliability and is used in maintenance planning and reliability analysis. MTBF is typically expressed in hours and is calculated by dividing the total operating time of a population of identical equipment by the total number of failures observed during that period. A higher MTBF indicates greater reliability. For example, if ten identical pumps are operated for 10,000 hours and two failures are observed, the MTBF would be (10 pumps 10,000 hours) / 2 failures = 50,000 hours. This means that, on average, each pump is expected to operate for 50,000 hours before experiencing a failure. MTBF is used to predict maintenance intervals, optimize spare parts inventory, and assess the overall reliability of a system. It's important to note that MTBF is a statistical average and does not guarantee that a particular piece of equipment will operate for that exact duration without failure.