Tool replacement policy for probabilistic tool life and random wear process

This study presents a tool replacement model which determines the optimal initial tool setting, tool adjustment cycle and tool replacement time with regard to quality loss, adjustment cost, replacement cost and penalty cost for possible tool failure. A quadratic loss function is employed to characterize the costs representing part quality. The Bernstein probability density function is applied to describe the usual characteristics of tool life and the tool wear process. Then, based on the considered costs, the best strategy for tool replacement can be determined. A possible application of the model is given that provides a method of off-line tool management in a production environment.