MTBF (Mean Time Between Failures) is a reliability metric that measures the average time between failures of a system or component. It is commonly used in the field of reliability engineering to assess the reliability of products or systems. MTBF provides an estimate of how long a device or system is expected to operate before experiencing a failure. It is usually expressed in hours.

Power Adapter lifetime refers to the expected lifespan or duration of usability for an adapter. It can be influenced by factors such as the quality of materials used, manufacturing processes, and usage conditions. The adapter lifetime is typically determined based on factors specific to the device and is often provided by the manufacturer as an estimated value.

Life Cycle is found by using the temperature rise of electrolytic capacitors under maximum operating temperature to estimate the approximate life of the power supply. For example, RSP-750-12 MTBF=109.1K hours(25°C); electrolytic capacitor C110 Life Cycle=213K hours (Ta=50℃)

DMTBF (Duty Mean Time Between Failures) is a variation of MTBF that takes into account the duty cycle of a system or component. The duty cycle represents the operational time compared to the total time, taking into consideration factors such as system downtime for maintenance or non-operational periods. DMTBF provides a more accurate reliability prediction for systems or components that do not operate continuously at full capacity.

MTBF Calculation

MTBF is calculated by taking the total time an asset is running (uptime) and dividing it by the number of breakdowns that happened over that same period of time.

MTBF = Total uptime / # of Breakdowns

Broken down, the MTBF calculation might look like this:

 Find the total uptime: Imagine you have a warehouse full of widgets, and 40 of them were tested for 400 hours each. The total hours spent testing equal 16,000 hours (40 x 400 = 16,000).

 Figure out the number of failures: Identify the number of failures over the entire number of widgets tested. For this example, consider there were 20 widget failures.

 Calculate MTBF: Now that we know testing was performed for 16,000 hours with 20 widget failures, we can calculate MTBF: 16,000 hours / 20 failures = 800 hours.