To increase the production in mines, it is essential to increase the availability of heavy earth moving machinery (HEMM). A number of maintenance schedule exists for maintenance of HEMM. A new type of maintenance schedule namely "noise spectrum based maintenance" is introduced in this book. This type of maintenance is a type of "preventive maintenance" as opposed to the historical practice of "periodic maintenance" based solely on operating hours. In this case "preventive" refers to premature or significant acoustical degradation as opposed to operational degradation. One major advantage of this maintenance strategy is its simplicity. It requires only the noise spectrum to be obtained at regular intervals for HEMM. The maintenance approach reported in this book are based on extensive experimental work carried out in the field and therefore can be confidently used by the mining industry. This book will be of immense help to maintenance personnel in mining industry, academicians and researchers working in Mining Engineering domain.