Full definition
The expected operational duration of a component or system before it requires replacement due to wear, degradation, or loss of function, expressed in hours, years, cycles, or distance depending on the application. Typical industrial service life targets: V-belts 15,000-25,000 hours (3-5 years at single shift), timing belts 10,000-25,000 hours, automotive serpentine belts (EPDM) 60,000-100,000 miles, roller bearings L10 30,000-100,000 hours (depending on load and speed per ISO 281), mechanical seals 20,000-40,000 hours, and conveyor belt covers 5-15 years. Factors that reduce service life: overloading (exceeding design capacity), misalignment (belt and bearing life halved by 0.1 mm offset), under/over-tensioning (each reduces belt life 30-50%), elevated temperature (each 10°C above rated reduces rubber life 50% per Arrhenius), chemical attack (incompatible fluids), contamination (particle ingress in bearings), and inadequate maintenance. Service life prediction methods: manufacturer catalog data (reference conditions), Weibull statistical analysis of field failure data, and accelerated life testing (ALT). The economic optimum is to replace components just before failure — achieved through condition monitoring (PdM) and trending. Per manufacturer life specifications and reliability engineering methodology.