Condition based maintenance first appeared in the late 1940's in the Rio Grande Railway Company, to detect coolant and fuel leaks in a diesel engine's lubricating oil. They achieved outstanding economic success in reducing engine failure by performing maintenance whenever "any" glycol or fuel was detected in the engine oil. The U.S. army, impressed by the relative ease with which physical asset availability could be improved, adopted those techniques and developed others. During the 50's, 60's, and early 70s CBM grew in popularity and a vibrant CBM technology industry emerged providing training, products, and services which came to be known as "predictive maintenance".

-----------------------------------------