Current workforce size $25$ Full$-$time

Inventory carrying cost $$10$ per unit$/$month

Backorder cost $$20$ per unit$/$month

Hiring and traning cost $$400$ per employee

Lay$-$off cost $$300$ per employee

Regular Time Production $$200$ per unit

Over$-$time capacity $30\%$ of Regular Time Production

Over$-$time cost $$300$ per unit

Subcontracting capacity $500$ units per month

Subcontract Cost $$350$ per unit

Production rate $2$ units$/$worker$/$day

Ignore Idle time of employees, if any