Freddybaby
The definition of "lifetime" varies among manufacturesrs. However, a failure is not necessarily a catastrophic failure. Lifetime is usually defined as the time, under specified operating conditions, at which either the capacitance decreases by a specified percentage, or the ESR increases by a specified percentage. Either of these conditions is considered a "failure". By this definition a capacitor could "Fail" and still operate perfectly in a circuit. Most designers specify a capcaitance that is higher than required in order to allow for degradation in capacitance over time. Similarly, a capacitor with a lower than required ESR is usually specified. See the following site for a detailed explanation of what's going on.
.
**broken link removed**
Regards,
Kral
Added after 3 minutes:
Sorry! The website is **broken link removed**.