if you buffer things up, you don't know where the problems in your production are
This is just stupid. If you're keeping an eye on things, of course you'll figure out which of your buffers are draining faster than they're filling - and the beauty of using buffers is that it gives you time to add more inputs or decrease outputs without ever having everything come to a screeching halt because you ran out of something important. In Factorio for example if you run out of whatever you're using for power generation, that can cause a cascading failure where everything suddenly breaks down.
In the real world JIT is used because warehouses cost money and capitalists want to reduce that cost. Any sane, planned system that didn't have this consideration would of course include buffers because they allow you to absorb supply shocks.
This is just stupid. If you're keeping an eye on things, of course you'll figure out which of your buffers are draining faster than they're filling - and the beauty of using buffers is that it gives you time to add more inputs or decrease outputs without ever having everything come to a screeching halt because you ran out of something important. In Factorio for example if you run out of whatever you're using for power generation, that can cause a cascading failure where everything suddenly breaks down.
In the real world JIT is used because warehouses cost money and capitalists want to reduce that cost. Any sane, planned system that didn't have this consideration would of course include buffers because they allow you to absorb supply shocks.