Exactly. You can say "oh, just take the machine out of production for a bit do software patching". However that reduces the uptime for your tool which will requ

Exactly. You can say "oh, just take the machine out of production for a bit do software patching". However that reduces the uptime for your tool which will require buying more of them to get the same throughput. More tools is not only capex, but also space on the factory floor. This is extra true for my company. We sell sorters, which don't actually do anything useful in terms of processing the wafers. The tools just shuffle the wafers between FOUPs. While these tools help customers optimize processes by changing batch sizes and such, they really want to have as few non-process tools as possible. So uptime is really important.