PA 122 Sarahs Organic Soap Company makes organic Sarahs Orga
Solution
Average daily demand (d) = 1500 kg
Number of days in a year = 5 days x 52 weeks = 260 days
Annual demand (D) = D x number of days per year = 1500 x 260 = 390000 kgs
Ordering cost (S) = $56
Cost per kg = $4.5
Holding cost (H) = 25% of cost = 25% of $4.5 = $1.13
a) Economic order quantity = sqrt of (2DS /H)
= sqrt [(2 x 390000 x 56) / 1.13]
= 6217.30 or rounded to 6217 kgs
So in order to minimize the annual Ordering and holding cost she should purchase 6217 kgs per order
b) If order quantity (Q) = 3500 kg
Annual Ordering cost = (D /Q) S = (390000/3500)56 = $6240
Annual holding cost = (Q/2)H = (3500/2)1.13 = $1977.5
Total cost = Ordering cost + Holding cost
= $6240 + $1977.5
= $8217.5
C) If order quantity (Q) = 8200 kgs
Annual Ordering cost = (D /Q) S = (390000/8200)56 = $2663.41
Annual holding cost = (Q/2)H = (390000/2)1.13 = $220350
Total annual cost = Ordering cost + Holding cost
= $2663.41 + $220350
= $223013.41
Total cost per kg = Total annual cost / D
= $223013.41/390000 kg
= $0.57 per kg
d) If the order quantity (Q) = 15000 kg
Cost per kg = $4.5 - (5% of $4.5) = $4.5 - $0.23 = $4.27
Holding cost (H) = 25% of cost = 25% of $4.27 = $1.07
Annual Ordering cost = (D/Q) S = (390000/15000)56 = $1456
Annual holding cost = (Q/2)H = (15000/2)1.07 = $8025
Total annual cost = Ordering cost + Holding cost
= $1456 + $8025
= $9481

