Flow improvement must include throttling, wherever necessary.
There seems to be a misconception in some supply chain teams that flow improvement means increasing the flow of products. While it is true for the whole system, it should not be applied to various sub-systems.
Flow improvement refers to maintaining smooth and uninterrupted flow through the entire system. We should maximize flow at the system constraint. However, all other non-constraints must resort to throttling to prevent excess build-up.
Improvement means flow increase at the constraint and flow throttling at non-bottlenecks.