expansion rate; growth rate
Technical term used in contexts such as business, infrastructure, or capacity planning to describe the rate at which something is being expanded or added.
We expect the facility expansion rate next fiscal year to increase by 5% compared to the previous year.
The line expansion rate in this area is not keeping up with demand.
Compound of 増設 (expansion, addition of facilities) and 率 (rate). The exact historical derivation is uncertain, but the components are transparent.