Reliability aspect of CNC machines-are we ready for integration?

Increasing availability of CNC machines is important if they are to be successfully integrated into flexible systems. In this study we look at the maintenance records from 7 CNC machines and 2 machining centres to find out what causes machines to fail and what costs are incurred by the user. Our results suggest that mechanical and electrical subsystems each cause the biggest number of breakdowns, closely followed by failures of hydraulic equipment, human-related failures and failures caused by the operating environment. Three main contributors to the maintenance budget are mechanical failures, permanent electronic failures and failures caused by humans. CNC machines are sophisticated pieces of machinery and require a range of techniques to reduce down-time. We hope that the results of our case study will provide a better insight into the problem