Statistical methods for evaluating the effect of operators on energy efficiency of mining machines

Research has recognised operators' skill as important factors affecting performance and energy efficiency of mining equipment. Modern monitoring tools generate large, highly variable, and, often, skewed energy efficiency data sets. Well-conceived statistical tests should be used to assess the effect of operators on energy efficiency in such situations. However, in many cases in the mining literature, the choice of statistical tests to evaluate operator effects has not been systematic and rigorous and, often, the underlying assumptions of these tests have not been examined before their use. This work provides a systematic method, synthesised from the statistical literature, to rigorously evaluate the effect of operators on energy efficiency of mining equipment. Mine engineers and managers can use this method to evaluate whether differences exist in energy efficiency of their operators given sample data and focus on operator training, if they find cause to improve operator performance.