工程经济学讲义_公共项目评价讲述.ppt

11.7 The Benefit-Cost-Ration Method Conventional B-C ratio with AW Where AW(?) = annual worth of (?); B = benefits of the proposed project; CR = capital-recovery amount(equivalent annual cost of the initial investment); OM = operating and maintenance costs of the proposed project Modified B-C ratio with AW * 11.7 The Benefit-Cost-Ration Method Conventional B-C ratio with PW, considering MV Where PW(?) = present worth of (?); B = benefits of the proposed project; I = initial investment in the proposed project; MV = market value of investment OM = operating and maintenance costs of the proposed project Modified B-C ratio * 11.7 The Benefit-Cost-Ration Method Considering disbenefits Where AW(?) = annual worth of (?); B = benefits of the proposed project; D = disbenefits of the proposed project CR = capital-recovery amount(equivalent annual cost of the initial investment); OM = operating and maintenance costs of the proposed project * 11.8 Evaluating Independent Projects by B-C Ratios Independent projects are categorized as groupings of projects for which the choice to select any particular project n the group is independent of choices regarding any and all other projects within the group Solution Any option is acceptable once its B-C ratio is greater than one Shortcomings Unrealistic under conditions of capital rationing * 11.9 Comparison of Mutually Exclusive Projects by B-C Ratios Mutually Exclusive Projects are defined as a group of projects from which, at most, one project may be select. The best alternative can be selected by maximizing the PW. Common mistake Maximizing B-C ratio ≠ Maximizing PW because B-C method provides a ratio rather than a direct measure of each project’s profit potential. Solution ? Incremental Benefit Cost Procedure * * Calculate Equivalent Worth (PW, AW, or FW)of Costs for Each MEA Rank-Order MEAs by Increasing Equivalent Worth of Costs Select “Do-Nothing” or Least Equivalent Cost MEA as Baseline Calculat