工程经济学第六章(英文版)

There are two basic types of alternatives.
Investment Alternatives Those with initial (or front-end) capital investment that produces positive cash flows from increased revenue, savings through reduced costs, or both.
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Larger Alternatives
For alternatives that have a larger investment than the base…
If the extra benefits obtained by investing additional capital are better than those that could be obtained from investment of the same capital elsewhere in the company at the MARR, the investment should be made.
B
-$125,000 $41,000
Both alternatives are attractive, but Alternative B provides a greater present worth, so is better economically.
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Cost Alternatives
This says that you often need to consider additional information such as strategic and qualitative input in project selection.
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Key to Success
Best businesses tend to rely on multiple (2 to 3) different methods for project selection; e.g. financial, scoring, strategic, etc. 3 Main Goals of Project Selection
-$25,000
-$60,000
-$30,000
Alternative D costs less than Alternative C, it has a greater PW, so is better economically.
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Study Period
Study Period – the study period (or planning horizon) is the time period over which alternatives are compared, and it must be appropriate for the decision situation.
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Investment Alternatives
Example: Use a MARR of 10% and useful life of 5 years to select between the investment alternatives below.
Alternative
A
Capital investment Annual revenues less expenses -$100,000 $34,000
Approaches to Project Selection
Basic Techniques Additional Techniques
• •
• •
Checklist/ Scoring Mapping/Balancing
Strategic Alignment Financial models
• •
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Investment & Cost Alternatives
Example
MARR = 10%
1. PWA= $9,738 Base Alternative 2. PWB = $10,131 is higher so the additional investment is justified and Alternative B is preferred.
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Popularity of Project Selection Approaches
Financial Methods for Project Selection are the most popular techniques used in business today therefore you must understand these techniques to be successful.
• For investment alternatives the PW of all cash flows must be positive, at the MARR, to be attractive. Select the alternative with the largest PW. • For cost alternatives the PW of all cash flows will be negative. Select the alternative with the largest (smallest in absolute value) PW.
• Decisions among feasible design alternatives.
• The decisions considered are those selecting from among a set of mutually exclusive alternatives—when selecting one excludes the choice of any of the others.
• MEAs can have equal lives (in which case the study period used is these equal lives), or they can have unequal lives, and at least one does not match the study period. • The equal life case is straightforward, and was used in the previous two examples.
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Base Alternative
Apply this rule, based on Principle 2 from Chapter 1.
Base Alternative - The alternative that requires the minimum investment of capital and produces satisfactory functional results will be chosen unless the incremental capital associated with an alternative having a larger investment can be justified with respect to its incremental benefits.
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Mutually Exclusive Alternatives (MEAs)
• Alternatives are examined on the basis of economic considerations alone. • Alternatives may have different initial investments and their annual revenues and costs may vary. • Alternatives must provide comparable ―usefulness‖: performance, quality, etc. • The basic methods from chapter 5 provide the basis for economic comparison of the alternatives.
1. Maximize the value of projects • Financial Methods • Scoring Models
Financial Methods are usually required and expected as a minimum criteria for 2. Balance the portfolio of projects all project proposals • Strategic Mapping and project selection 3. Strategic alignment of projects with decisions. business goals and objectives • Roadmaps • Strategic Allocation
Example: Use a MARR of 12% and useful life of 4 years to select between the cost alternatives below.
Alternative C D
Capital investment
Annual expenses
-$80,000
3. PWdiff = -$13,000 +$4,225(P/A,10%,4) = $393
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Investment & Cost Alternatives
Example