Reliable tool replacement policy for quality and cost

A tool management model is developed which determines the optimal initial tool setting and tool replacement time in consideration of balancing quality loss, replacement cost, and possible tool failure. A quadratic loss function is employed to characterize the costs resulting from the deviation of part dimension from its target value. The tool reliability function is used to represent the probability of possible tool failure. The model development does not attempt to explain the underlying physics of tool wear and tool failure and does not intend to apply to on-line tool replacement decision. Instead, the present study provides a decision model for management engineers in off-line tool management applications.