TABLE OF CONTENTS Age exploration is the systematic examination of the lifetime a component or part can support in an application in service. It's crucial to setting task intervals. The term means literally "to explore component aging, and find out what service the component can provide."
It used to be assumed that all components had finite lifetimes equipment wore out and needed replacement or overhaul. As first examined in air transport, it was discovered that it doesn't hold true for many components. Though powerful and intuitive, the assumption had no basis. A statistically large number of components showed virtually no deterioration during period of use, based upon early jet engine overhauls in the late 1950s and early 60s. These included actuarial analysis of failure studies. On 90% of replaced components, life remained at the end of their specified life.
"Lifetimes" have always been based on the best available information. Aircraft turbine development transitioning from prescribed overhauls to age study-based monitoring summarizes the experience. When overhaul limits were eliminated and age exploration undertaken, equipment lifetimes increased significantly resulting in quick economic benefits and lower risk. Considerable actuarial analysis detailed mathematical failure analysis to quantify lifetimes and conditional probability distributions-and support this change. The concept of "conditional overhaul" gradually emerged. The results can be applied to most other industrial maintenance applications.
Conditional overhauls only address immediate failure causes and correct other necessary parts to achieve specified performance. The paradox is that conditional overhauls yield "overhauled" equipment that statistically perform the same as traditionally overhauled...
