I never understood this type of calculation as it implies that time is directly converted into money. However, I struggle to come up with an example for this. Even the most trivial labor cases like producing paperclips don't seem to be directly converting time into profit: even you will make 10k units instead of 100k this hour, you don't sell them immediately. They bring revenue to the firm via a long chain of convoluted contracts (both legal and "transactional") which are very loosely coupled to the immediate output.
Nothing is operating at minute margins unless it's explicitly priced on a minutely basis, like a cloud service. Even if a worked on a conveyor belt can't produce paperclips without looking at Google Docs sheet all the time, this will be absorbed by the buffers down the line. And only if the worker will fail to meet her monthly target due to this, loss of revenue might occur. But in this case the service has to be down for weeks.
In case of more complex conversions of time into money, like in the most of intellectual work, this is even less obvious that short downtimes will cause any measurable harm.
Nothing is operating at minute margins unless it's explicitly priced on a minutely basis, like a cloud service. Even if a worked on a conveyor belt can't produce paperclips without looking at Google Docs sheet all the time, this will be absorbed by the buffers down the line. And only if the worker will fail to meet her monthly target due to this, loss of revenue might occur. But in this case the service has to be down for weeks.
In case of more complex conversions of time into money, like in the most of intellectual work, this is even less obvious that short downtimes will cause any measurable harm.