Assessing the efficiency of maintenance operators: A case study of turning railway wheelsets on an under-floor wheel lathe

This article assesses the technical efficiency of different operators turning railway wheelsets on an under-floor wheel lathe. This type of lathe is a computer numerical control machine used to turn wheelsets in situ on the train. As railway wheels are turned, a certain amount of the wheel diameter is lost to restore the tread profile and full flange thickness of the wheel. The technical efficiencies of the different wheel lathe operators are assessed using a stochastic frontier analysis, while controlling for other explaining variables such as the flange thickness and the occurrence of rolling contact fatigue defects, wheel flats and cavities. Different model specifications for the stochastic frontier analysis are compared with linear mixed model specifications, showing that the stochastic frontier analysis model exhibits a better Akaike information criterion.