Fix quantities and check them against the minimum
Pieces per style, colour and size; the factory’s minimum is set by the fabric mill, not the sewing line.
NUMBER: the minimum (the factory’s; no public figure)
Fix pieces per style, per colour and per size before anyone quotes, because the factory’s minimum is counted per style and per colour, not per order. Three styles in two colours each is six production runs, and the minimum for each run is usually set by the fabric mill’s minimum dyeing lot rather than by the sewing line.
The minimum is the factory’s number. There is no public figure, because there is no such thing as one: it moves with the factory, the fabric and the construction, and a factory that runs 300 pieces of one cloth will not run 300 of another. The office puts the real minimum in writing in the first quote, and tells you straight if your quantity cannot run properly.