TBF, or mean time between failure, is called "mean time between failure" in English. It is an index to measure the reliability of a product (especially electrical products). The unit is "hours" It reflects the time quality of the product and is an ability to maintain the function of the product within a specified time. Specifically, it refers to the average working time between two adjacent faults, also known as the average fault interval. It only applies to repairable products. At the same time, it is also stipulated that the ratio of cumulative working time to failure times in the total use stage of the product is MTBF. Generally, the MTBF of disk array products cannot be less than 50,000 hours.

In other words, it is very important that the time from the purchase to the first maintenance of a disk array must be greater than or equal to 50,000 hours before the product meets the requirements.