In: Operations Management
Solution:
Annual demand (D) = 10,300 wheel bearings
Setup cost (S) = $42
Holding cost (H) = $0.70 per wheel bearing per year
Daily production (p) = 530 wheel bearings per day
Daily Demand (d) = 48 bearings
(a) Optimum production quantity (Q):
Q = SQRT [(2 x D x S) / H x (1 - d/p)]
Q = SQRT [(2 x 10,300 x $42) / $0.70 x (1 - 48/530)]
Q = 1,165.80 or 1,166 (Rounding off to the nearest whole number)
Optimum production quantity (Q) = 1,166 units
(b) Maximum inventory (Imax):
Imax = Q x (1 - d/p)
Imax = 1,166 x (1 - 48/530)
Imax = 1,060.4 or 1,060 (Rounding off to the nearest whole number)
Maximum inventory = 1,060 units
(c) Number of production runs:
Production runs = Annual demand / Production quantity
Production runs = 10,300 / 1,166
Production runs = 8.83 runs
(d) Setup plus holding cost:
Total Setup cost = (Annual demand / Production quantity) x Setup cost
Total Setup cost = (10,300 / 1,166) x $42
Total Setup cost = $371.01
Total holding cost = (Q/2) x H x (1 - d/p)
Total holding cost = (1,166/2) x $0.70 x (1 - 48/530)
Total holding cost = $371.14
Total cost = Total Setup cost + Total holding cost
Total cost = $371.01 + $371.14
Total cost = $742.15