Corrective work is performed following preventive maintenance when __________.

Corrective work is performed following preventive maintenance when problems are discovered. This approach is fundamental in total productive maintenance because it aims to address issues that arise even after preventive measures have been implemented. Preventive maintenance is designed to reduce the likelihood of equipment failure, but it is impossible to anticipate every potential problem. When an issue does occur, corrective actions are needed to restore the system's functionality and ensure that operations can continue smoothly.

Addressing problems promptly after they are discovered is essential for minimizing downtime and maintaining production efficiency. By identifying and rectifying issues quickly, organizations can maintain high levels of productivity and extend the life of their equipment. This practice is in line with TPM principles, which prioritize proactive management of equipment and continuous improvement in processes.

Scheduled maintenance occurs as part of a planned program, not necessarily in response to issues, so it doesn't directly tie in with the initiation of corrective work. Similarly, the replacement of machinery does not inherently relate to corrective work following preventive maintenance since it involves replacing rather than fixing existing issues. Lastly, suggesting that corrective actions only take place when all preventive actions have failed overlooks the opportunity for proactive maintenance and conflict resolution at the first sign of a problem.