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IENG 217 Cost Estimating for Engineers. Project Estimating. Hoover Dam. U.S. Reclamation Service opened debate 1926 Six State Colorado River Act, 1928 Plans released 1931, RFP Bureau completed its estimates 3 bids, 2 disqualified Winning bid by 6 companies with bid price at $48,890,955
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IENG 217Cost Estimating for Engineers Project Estimating
Hoover Dam • U.S. Reclamation Service opened debate 1926 • Six State Colorado River Act, 1928 • Plans released 1931, RFP • Bureau completed its estimates • 3 bids, 2 disqualified • Winning bid by 6 companies with bid price at $48,890,955 • Winning bid $24,000 above Bureau estimates
Project Methods • Power Law and sizing CERs • Cost estimating relationships • Factor
Power Law and Sizing • In general, costs do not rise in strict proportion to size, and it is this principle that is the basis for the CER
Power Law and Sizing • Ten years ago BHPL built a 100 MW coal generation plant for $100 million. BHPL is considering a 150 MW plant of the same general design. The value of m is 0.6. The price index 10 years ago was 180 and is now 194. A substation and distribution line, separate from the design, is $23 million. Estimate the cost for the project under consideration.
Factor Method Uses a ratio or percentage approach; useful for plant and industrial construction applications
Factor Basic Item Cost Factor Method
Example; Plant Project 4.1 1.7 1.1
Other Project Methods • Expected Value • Range • Percentile • Simulation
A A A A A MARR = 15% 1 2 3 4 5 10,000 Expected Value Suppose we have the following cash flow diagram. NPW = -10,000 + A(P/A, 15, 5)
2 , 000 p 1 / 6 A 3 , 000 p 2 / 3 4 , 000 p 1 / 6 Expected Value Now suppose that the annual return A is a random variable governed by the discrete distribution:
2 , 000 p 1 / 6 A 3 , 000 p 2 / 3 4 , 000 p 1 / 6 Expected Value For A = 2,000, we have NPW = -10,000 + 2,000(P/A, 15, 5) = -3,296
2 , 000 p 1 / 6 A 3 , 000 p 2 / 3 4 , 000 p 1 / 6 Expected Value For A = 3,000, we have NPW = -10,000 + 3,000(P/A, 15, 5) = 56
2 , 000 p 1 / 6 A 3 , 000 p 2 / 3 4 , 000 p 1 / 6 Expected Value For A = 4,000, we have NPW = -10,000 + 4,000(P/A, 15, 5) = 3,409
Expected Value There is a one-for-one mapping for each value of A, a random variable, to each value of NPW, also a random variable. A 2,000 3,000 4,000 p(A) 1/6 2/3 1/6 NPW -3,296 56 3,409 p(NPW) 1/6 2/3 1/6
Expected Value E[Return] = (1/6)-3,296 + (2/3)56 + (1/6)3,409 = $56 A 2,000 3,000 4,000 p(A) 1/6 2/3 1/6 NPW -3,296 56 3,409 p(NPW) 1/6 2/3 1/6