Energy consumption modeling for machine tools after preventive maintenance

Energy consumption of a machine tool increases dramatically as reliability decreases, which indicates performance degradation. From the perspective of near-zero downtime and energy conservation, preventive maintenance is usually carried out. This research aims at modeling the energy consumption of machine tools after they are maintained preventively. The relationship between reliability and energy consumption is modeled based on historical data and then the energy consumption of a machine tool is calculated. Reliability is modeled by Weibull distribution, the parameters of which are estimated utilizing the Maximum Likelihood Estimation method. Reliability after preventive maintenance is modeled by employing Malik's Proportional Age Reduction model. The carbon emission is assessed referring to the standard developed by the Climate Registry in North America.