Abstract This paper describes a procedure to determine the optimum tool set for a batch of turned components, the optimisation criterion being either the minimum machining cost or minimum number of machine stoppages or a combination of both. A tool-operation-cost table is constructed wherein the costs of machining an operation with individual tools are stored and the optimum tool set is obtained by searching this table exhaustively. The wear rate of each tool is adjusted so that it machines an integral number of components; to reduce the machine stoppages, tool wear rates of the leading and shadowing tools are further adjusted so that tool changes are synchronised. The factors considered in the optimisation include the number of turret positions, batch size and performance of individual and sister tools. To demonstrate the system, tool sets have been determined for a turned component for different optimisation criteria.