Tea gardens buy through a process
Gardens build and maintain year round — worker housing, factory buildings, drainage, roads — through a purchase process with a store that logs what arrives. A referenced invoice and a challan naming the vehicle and receiver are what reconcile against their records at month end.
Monsoon compresses the building window
The Brahmaputra belt has months where roads and crossings are unreliable, which concentrates construction into a shorter season. Stocking ahead of it is a decision taken once, and last season's movement over the same weeks is the basis for it.
Long inbound supply lines
Material reaches upper Assam after a long journey, making inbound freight a substantial part of landed cost and lead times long enough that a stockout cannot be fixed quickly. Recording freight against the purchase gives a cost you can price from.