Abstract: Effective control of tool replacement is of great significance for reducing losses in downtime and improving productivity of production line. The differences between preventive tool replacement and corrective tool replacement are analyzed. The uncertainty of the corrective tool replacement time is described. A cost model for tool replacement time is developed. Taking into account both the uncertainty of tool life and time for performing corrective tool replacement, a decision-making model for tool replacement cycle is established and the objective is to minimize the average cost per unit part. An algorithm based on the golden section method is given for obtaining the optimal tool replacement cycle. Effects of the parameters such as the expectation of equipment inspection and fault diagnosis time, shape parameter and scale parameter of Weibull tool life distribution on the optimal tool replacement cycle are investigated. An example is presented finally to illustrate the proposed tool replacement approach.

Key words: tool replacement;corrective maintenance;decision model;uncertainty