Demand and working days December January February March April May Forecasted demand 2,500 2,200 1,900 1,750 1,950 2,600 Number of working days 19 22 19 21 20 21 Relevant costs/information Inventory Total material cost $45.00 Beginning inventory 225 units Inventory holding cost $2.00 Safety stock 10%/month demand Marginal cost of subcontracting $50.00 Hiring and training cost $800.00 Layoff cost $2,200.00 Straight time cost $6.00 Labor hours required 8/unit