If you use injection moulding or diecasting tools with large numbers of cavities, you may run the tool with one or more cavities blocked or frozen off.
When this happens you can tell FIS that you have lost one or more cavities. This enables FIS to correctly count the number of parts made in each cycle of the machine.
Eventually you may stop the machine and fix all cavities. You can then tell FIS that no cavities are blocked again.