Bearings are important in all rotating applications. First priority is to select a bearing type and size that will withstand the magnitude and direction of applied duty-cycle loading. Predicting bearing durability (by analysis, testing, and past experience) is another step that approximates how long bearings can operate before failure. This is useful where warranty or replacement claims caused by premature bearing breakdowns are costly.

Failure investigations show that it's difficult to predict all possible causes of bearing problems. However, quality-controlled production and systematic analysis (early in the design cycle) increase successful machine operation and decrease downtime.