5 Material Cost Cost = unit Price x Quantity KEYS Fluctuation of unit priceQuantity of Material useCombination of materialsExample: Activity AConcrete 10m3 = 2,000x100 = 20,000Steel 1 ton = 1,500x 1 = 1,500Formwork = 1,000 x300 =300,000Material Cost = 321,500 Baht
6 Labor Cost Cost = Unit price x Duration x Numbers Duration depends on productivity rateExample Activity A20 Carpenters for 10 Days 300 Baht/man/Day10 Labors for 10 Days 150 Baht/Man/DayLabor Cost = (20x10x300)+(10x10x150)= 60, ,000 = 75,000 BahtO.T RateBonus Rate
7 Labor Cost Productivity Rate examples 1 labor 3 sq.m. brick wall per day1 Carpenter 1 footing formwork/daySubcontract Rate examples300 Baht/1 Door installation50 Baht/1 meter installation3 Baht/1 Kg of Steel reinforcementNormally subcontract rate is more expensive.
8 Equipment Cost O & O Cost O1 - Owning Cost Example You bought A Honda 600,000 Baht and sold it 5 years later at 300,000 BahtYou paid 600, ,000 = 300,000 for 5 yearsApproximately;You do pay 300,000/365/5 = Baht/Day owning this Honda*** Do not forget interest, taxes, inflation, etc.
10 Equipment Cost An example You use an excavator for a trench excavation 100m31 round of operation the excavator can take 0.1 m31 round of the operation takes 30 seconds (Load - Turn-Dump-Turnback)1 Hour productive time = 40 min1 Hour, the excavator can produce = 80 rounds * 0.1 m3 = 8 m3To finish the excavation, it takes 100/8 = 12.5 HoursEquipment Cost = 12.5*58.5 (assume) = Baht
11 Common Errors in Cost Estimation Forget items in WBSPoor productivity estimationSome hidden cost and riskTemporary worksWrong unit price, Market conditionWrong quantity estimation, Human errorMissing in quality of workTransportation