Item Kites Wind Socks

Demand forecast $32,000$ units$/$year $12,000$ units$/$year

Lot size $20$ units $60$ units

Standard processing time $0\mathrm{.}2$ hour$/$unit $1\mathrm{.}0$ hour$/$unit

Standard setup time $3\mathrm{.}0$ hours$/$lot $4\mathrm{.}0$ hours$/$lot

The number of additional machines required is