Certification introduction
MTBF certification refers to the certification of the mean time between failures of a product. The full English name is "Mean Time Between Failure". In fact, MTBF refers to the MTBF test report, which is a report on product reliability prediction. MTBF is a reliability indicator that measures the reliability of a product (especially electrical products). The unit is "hour". It reflects the time quality of the product and is the ability of the product to maintain functionality within a specified time. Specifically, it refers to the average working time between two adjacent failures, also known as the mean time between failures. In summary, a product with fewer failures means high reliability. The ratio of the total number of product failures to the total number of life units is called the "Failure rate". It only applies to repairable products. At the same time, it is also stipulated that the ratio of the cumulative working time of the product to the number of failures during the total use period is MTBF. Generally, the MTBF of disk array products cannot be less than 50,000 hours.

MTBF data calculation
Suppose the MTBF of a computer is 30,000 hours. Is it detected by running the computer continuously for 30,000 hours? Of course not, otherwise there would be so many products that would take decades to be tested. The most common and authoritative standard for calculating MTBF value is MIL-HDBK-217 (proposed by the Reliability Analysis Center and Rome Laboratory and became an industry standard), which is specially used for Bellcore (proposed by AT&T Bell Laboratory and became the standard for MTBF of civilian products). Industry Standard).

The main consideration in MTBF calculation is the failure rate of each component in the product. However, since the failure rates of devices will vary greatly in different environments and usage conditions, these factors must be considered when calculating reliability indicators. These factors are almost impossible to calculate manually, but with the help of software such as MTBFcal and its huge parameter library, the MTBF value can be easily obtained. If a factory that works three shifts a day requires continuous operation for 24 hours and a failure-free rate P(t)=99% or more, the MTBF of the machine tool must be greater than 4500 hours. MTBF5000 hours requires higher and more complex production lines composed of different numbers of CNC machine tools. We only discuss a single machine tool here:

If the failure rate ratio between the host machine and the CNC system is 10:1 (the reliability of the CNC system is an order of magnitude higher than that of the host machine), the MTBF of the CNC system will be greater than 50,000 hours, and the CNC device, spindle and driving part, etc. The MTBF of the main part must be greater than 100,000 hours.

MTBF is not detected in actual operation, it is converted through the national standard detection algorithm. For example, Lenovo Yangtian's MTBF of 60,000 hours was obtained by submitting 192 Lenovo Yangtian computers for inspection. During a 40-day experimental period, the tested products were subjected to comprehensive changes in voltage, temperature, humidity, etc. at a specific frequency. Environmental stress, according to the corresponding relationship between electronic product reliability and time characteristics, the experimental results are converted using a standard data model. Similarly, the 100,000-hour MTBF of Tongfang Beyond E350 is calculated from 400 computers and 18 days of testing results.

In fact, we don’t need to pay attention to how to calculate the MTBF value. As long as we know that choosing products with high MTBF value will bring us higher competitiveness. Of course, the higher the MTBF value, the better. The higher the reliability, the higher the cost of the machine tool. Just choose moderate reliability according to actual needs.

The purpose of MTBF analysis
1. Key countermeasures against high-frequency faulty parts and the basis for technical transformation to extend the life of parts.
2. Calculate the life cycle of parts and prepare the best maintenance plan.
3. Regarding the selection of inspection objects and items and the setting and improvement of inspection standards.
4. Used to guide the allocation of internal and external maintenance work. Based on the evaluation of the company's equipment repair capabilities, the risks in terms of maintenance quality and equipment efficiency of the internal work are determined based on the type of equipment and types of operations, which serves as an important reference for maintenance outsourcing.
5. Set benchmarks for spare parts. The various reserve items and basic inventory quantities of mechanical and electrical parts should be judged based on MTBF record analysis to achieve the most economical inventory level.
6. Use it as a reference for selecting the key points for improvement of maintenance technology methods. In order to improve equipment availability, it is necessary to shorten the time for long-term maintenance work and engineering adjustments and switching related to equipment downtime. Therefore, it is necessary to inspect the maintenance operation method, and the basic information such as the items to be inspected and the selection of priorities need to be based on the MTBF analysis record sheet.
7. Used to set estimated operating time standards for equipment objects, as well as research on the selection of maintenance operations and maintenance time standards. The setting of estimated time standards for maintenance plans and the selection of maintenance operations must consider factors such as the equipment maintenance repetition cycle or the difference between the standard time value and the actual maintenance time, as well as the characteristics of the corresponding maintenance operations. Therefore, the MTBF analysis table is very necessary.
8. Reference for organizing drawings and reselecting key equipment or parts. MTBF's analysis record sheet records information such as equipment parts modification projects or friction deterioration, as well as equipment drawing modifications or pre-production, etc. Through frequent analysis and inspection and importance ranking management, engineering drawing management can be made easier.
9. Set and revise operating standards and determine the allocation of responsibilities for equipment maintenance business.
10. Provide technical information on equipment reliability and maintainability design. The most important thing about maintenance technology is to collect technical information about the reliability and maintainability design of equipment based on the MTBF analysis table, so as to provide it to the design department for reference when designing equipment.

MTBF Reference Standard
The reference standards usually corresponding to MTBF are:

Telcordia SR 232

Apply for MTBF information
Product BOM
product specifications
Product usage conditions
Do corresponding tests to obtain data on temperature rise, current or voltage.