What is MTBF? What is MTBF?

MTBF is the average failure time, English is "Mean times Between Failure", specifically refers to the product from one fault to the next failure average time, is the measure of a product reliability indicators (only for the failure of the repair or replacement parts can continue to work equipment or systems), the unit is " Hours. "

Specifically, it refers to the average working time between adjacent two failures, also known as the mean fault interval. It is only available for serviceable products. At the same time, it also stipulates that the ratio of working time to failure times of the product is MTBF.

Usually, we are in the product manual or packaging can see this MTBF value, such as 8,000 hours, 20,000 hours, then, the number of MTBF is calculated out of it, assuming a computer's MTBF for 30,000 hours, is this computer running for 30,000 hours continuously detected? The answer is no, in that case, we have so many products to be tested for decades. In fact, about the MTBF value of the calculation method, the current most common authoritative standard is mil-hdbk-217, gjb/z299b and Bellcore, respectively, for military products and civilian products. Among them, mil-hdbk-217 by the U.S. Department of Defense Reliability Analysis Center and Rome Laboratory proposed and become the industry standards, dedicated to the military products MTBF value calculation, gjb/z 299B is our military standards; and Bellcore is by At&t Bell The laboratory proposes and becomes the industry standard for calculating the MTBF value of commercial electronic products.

As far as MBTF itself is concerned, it is the stability index of the vast number of consumers. The higher the MTBF value, the better the stability of the PC. In fact, in order to protect the interests of the vast number of consumers, the provision of PC products MTBF to reach a certain level, China's MTBF average trouble-free working time is 4,000 hours. From a formal point of view, 4,000 hours is a more reasonable value, it is also the consumer can perceive the value.

How does the value of MTBF work out?

Suppose a computer's MTBF is 30,000 hours, is this computer running for 30,000 hours continuously detected? Of course not, otherwise there are so many products to be tested in decades. The most common authoritative standard for calculating the MTBF value is the mil-hdbk-217 (DoD Reliability Analysis Center and Rome laboratories are proposed and become industry standards, dedicated to military products), gjb/z299b (Chinese military standards) and Bellcore (at& T Bell Laboratory proposed and became the industry standard for civil product MTBF.

The failure efficiency of each component in the product is mainly considered in the calculation of MTBF. However, because the devices in different environments, different use conditions of its failure rate will be very different, so in the calculation of reliability indicators, we must consider these factors. These factors can hardly be calculated manually, but with the help of software such as mtbfcal and its large parameter library, it is easy to get the MTBF value.

The factory that works three shifts every day if requires 24 hours continuous operation, no failure rate P (t) =99% above, then the machine tool MTBF must be greater than 4,500 hours. MTBF5000 hours for a different number of CNC machine tools made up of the production line is higher and more complex, we only discuss a single machine:

If the main engine and CNC system of the ratio of 10:1 (CNC systems reliability is higher than the host a order of magnitude), CNC system MTBF will be greater than 50,000 hours, and the CNC device, spindle and drive part of the major parts of the MTBF must be greater than 100,000 hours.

In fact, we do not have to pay attention to the MTBF value of how to calculate, as long as we know the choice of MTBF value of products, will bring us a higher competitiveness.

Of course, is not the MTBF value of the higher the better, the higher the reliability of the high cost of machine tools, according to the actual need to choose the appropriate reliable on the line.

65,000 hours, 100,000 hours, what is this concept?

Take 100,000 hours, if we do not turn off the computer running, to run 11 years, if the daily run 10 hours of calculation, it will run for 27 years or so. Do not say that our PC has 27 years of life, even the 27 years of MTBF time, how to measure out? is a mystery!

MTBF is not detected in the actual operation, it is through the national standards of the detection algorithm conversion. For example, Lenovo's 60,000-hour MTBF, is through the submission of 192 Lenovo Yang-day computer, in the period of 40 days, to a specific frequency, the test products exert voltage, temperature, humidity and other comprehensive environmental stress, according to the reliability of electronic products and time characteristics of the corresponding relationship, The experimental results are converted using a standard data model. Similarly, the same side beyond the E350 100,000-hour MTBF is 400 computers, through the 18-day test results converted.

For PCs, in times that are sure to be updated every 4 years, is it necessary to have such a high MTBF value? What are the essential differences between 10,000-hour MTBF and 100,000-hour MTBF for consumers?

You know, when the PC's MTBF value reaches more than 10,000 hours, its computer stability has been quite good. Because of this, HP, Dell and other international PC manufacturers do not overemphasize the MTBF value, did not break the MTBF value of tens of thousands of hours as a product stability standards.

"MTBF is an important standard for PC stability, but when it exceeds a certain value, it has no special meaning, but other manufacturers are fried, we can not do it!" "Some insiders are so candid.