MTBF

MTBF, the average time between failures, the English name is "Mean Time Between Failure." It is a measure of the reliability of a product (especially electrical products). The unit is "hours." It reflects the quality of the product's time and is a capability that reflects the product's ability to maintain functionality within a specified time. Specifically, it refers to the average working time between two adjacent failures, also known as the average failure interval. It is only for repairable products. It also stipulates that the ratio of the cumulative working time to the number of failures in the total use phase of the product is the MTBF. The tape drive product MTBF value should not be less than 200,000 hours.

Usually, we can see the MTBF value in the product manual or package, such as 8000 hours, 20,000 hours, then, how does the MTBF value be calculated? Suppose a computer's MTBF is 30,000 hours, isn't it? The computer was continuously tested for 30,000 hours? The answer is no, if that is the case, we have so many products that can't be tested in decades. In fact, regarding the calculation method of the MTBF value, the most common authoritative standards at present are MIL-HDBK-217, GJB/Z299B, and Bellcore, which are used for military products and civilian products, respectively. Among them, MIL-HDBK-217 was proposed by the U.S. Department of Defense Reliability Analysis Center and Rome Laboratories and became the industry standard. It is specifically designed for the calculation of MTBF value of military products, GJB/Z 299B is the military standard of China, and Bellcore is powered by AT&T Bell. The laboratory proposes and becomes the industry standard for calculating the MTBF value of commercial electronic products.

The main consideration in the MTBF calculation is the failure rate of each device in the product. However, due to the device's failure rate in different environments and under different conditions of use, there will be great differences. For example, if the same product is in different environments, such as in the laboratory and offshore platforms, the reliability value is definitely different. Another example is a capacitor with a rated voltage of 16V must have a different failure rate at actual voltages of 25V and 5V. Therefore, when calculating the reliability index, the above factors must be taken into account. All of these factors can hardly be calculated manually, but with software such as MTBFcal software and its extensive parameter library, we can easily derive the MTBF value.

In fact, how to calculate the MTBF value is not our concern. We should focus on how much the value of a product's MTBF is. In terms of users, we should use products with high MTBF values.