Replacement time of a cutting tool subject to variable speed

Abstract

This paper studies the problem of finding the time to tool replacement when a tool is used under different sequential values of cutting speed. The proportional hazards model (PHM) is used to model the tool's reliability and hazard functions. The model's covariate is the cutting speed. Experimental data are obtained and used to construct and validate the PHM, which is then used in decision making. Three criteria for tool replacement are proposed. The results show that the PHM offers a very good representation of the reliability and the hazard functions at different speed values. These results are discussed and conclusions are drawn.