The satisfactory operation of a diesel engine depends on proper fueling, correct material and tolerances, and adequate lubrication and cooling. As with any manufactured item, there can be defects in design or manufacturing, but the more common causes of failure are poor maintenance, abuse, or a failure of a piece of supporting equipment. Although the mode of failure of any individual component can be individually determined, the failure analysis of an engine normally requires an evaluation of all of the interacting components.