Simulation of tool and part flow in FMSs

The authors deal with the problem of tool management in FMSs that are provided with a tool carrier. The paper reports on a procedure to determine how many copies of the various types of tools should be present and describes a simulation study that investigates the possibility of reducing the investment in tools by sharing the tools among several machining centres. The performance of the FMS is measured by the fraction of time that machining centres are unable to work because the tool required for the next imminent operation is not present in the tool magazine of the machining centre. These waiting times depend on the selection of tools available at the central tool magazine and on the tool management policy. The paper shows that by a proper management of the tool transport system it is possible to obtain savings in tooling while preserving the performance of the FMS.