A common question with fans, is “how long will a fan operate within my application?”. While this is an excellent question, the answer may not be apparent when comparing life measurements for fans to other electronic components used in an application. Before exploring the life of a fan, first, the customer needs to understand the different ways of measuring life and determine the best fan option. With fans, there are three common ways to define life: Mean Time Between Failure (MTBF), Weibull Curves, or L10 life. MTBF is very widely used to define the life of simple electronic components. This type of evaluation is based on the average life of a product when considering a large sample size. Weibull curves are used to define the failure rate of a product throughout the entire life cycle. Finally, the L10 life which is derived from bearing life calculations to define the time taken for 10% of a group of products to fail.