L:21 Incremental Analysis

1. L:21 Incremental Analysis ECON 320 Engineering Economics Mahmut Ali GOKCE Industrial Systems Engineering Computer Sciences

2. Comparing Mutually Exclusive Alternatives Based on IRR • Issue: Can we rank the mutually exclusive projects by the magnitude of its IRR? n A1 A2 -$1,000 -$5,000 $2,000 $7,000 100% > 40% $818 < $1,364 0 1 IRR PW (10%)

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4. Can’t Compare without Knowing Their Base Salaries For the same reason, we can’t compare mutually exclusive projects based on the magnitude of its IRR. We need to know the size of investment and its timing of when to occur.

5. Incremental Investment • Assuming a MARR of 10%, you can always earn that rate from other investment source, i.e., $4,400 at the end of one year for $4,000 investment. • By investing the additional$4,000 in A2, you would make additional$5,000, which is equivalent to earning at the rate of 25%. Therefore, the incremental investment in A2 is justified.

6. Incremental Analysis (Procedure) Step 1: Compute the cash flow for the difference between the projects (A,B) by subtracting the cash flow of the lower investment cost project (A) from that of the higher investment cost project (B). Step 2: Compute the IRR on this incremental investment (IRR ). Step 3: Accept the investment B if and only if IRR B-A > MARR B-A NOTE: Make sure that both IRRA and IRRB are greater than MARR.

7. Example 7.7 - Incremental Rate of Return Should we take project B1, B2 or neither? Perform an incremental IRR analysis! 17.43% 25%

8. Example 7.7 - Incremental Rate of Return Given MARR = 10%, which project is a better choice? Since IRRB2-B1=15% > 10%, and also IRRB2 > 10%, select B2.

10. IRR on Increment Investment:Three Alternatives Step 1: Examine the IRR for each project to eliminate any project that fails to meet the MARR. Step 2: Compare D1 and D2 in pairs. IRRD1-D2=27.61% > 15%, so select D1. D1 becomes the current best. Step 3: Compare D1 and D3. IRRD3-D1= 8.8% < 15%, so select D1 again. Here, we conclude that D1 is the best Alternative.

11. Practice Problem You are considering four types of engineering designs. The project lasts 10 years with the following estimated cash flows. The interest rate (MARR) is 10%. Which of the four is more attractive?

12. Incremental Analysis for Cost-Only Projects

13. Example 7.9 Incremental Cash Flow (FMS – CMS) IRR on incremental cash flows

14. Solution: Revenue generated same, service projects, compare based on costs

15. Ultimate Decision Rule: If IRR > MARR, Accept • This rule works for any investment situations • In many situations, • IRR = ROR • but this relationship does not hold for an investment • with multiple RORs.

16. Predicting Multiple RORs (Chapter 7A) - 100% < i*< infinity • Net Cash Flow Rule of Signs No. of real RORs (i*s) < No. of sign changes in the project cash flows

17. Example n Net Cash flow Sign Change 1 1 1 0 1 2 3 4 5 6 -$100 -$20 $50 0 $60 -$30 $100 • No. of real i*s  3 • This implies that the project could have (0, 1, 2, or 3) i*s but NOT more than 3.

18. Period Cash Flow Sum (n) (An ) Sn Accumulated Cash Flow Sign Test Find the accounting sum of net cash flows at the end of each period over the life of the project If the series S startsnegativelyand changes signONLY ONCE, there exists a unique positive i*.

19. Example nAnSn Sign change -$100 -$20 $50 0 $60 -$30 $100 -$100 -$120 -$70 -$70 -$10 -$40 $60 0 1 2 3 4 5 6 1 • No of sign change = 1, indicating a uniquei*. • i* = 10.46%

20. Example A.2 $3,900 $2,145 2 0 1 3 $1,000 $5,030 • Is this a simple investment? • How many RORs (i*s) can you expect from • examining the cash flows? • Can you tell whether or not this investment has a unique rate of return?

21. Summary Rate of return (ROR) is the interest rate earned on unrecovered project balances such that an investment’s cash receipts make the terminal project balance equal to zero. Rate of return is an intuitively familiar and understandable measure of project profitability that many managers prefer to NPW or other equivalence measures. Mathematically we can determine the rate of return for a given project cash flow series by locating an interest rate that equates the net present worth of its cash flows to zero. This break-even interest rate is denoted by the symbol i*.

22. Internal rate of return (IRR) is another term for ROR that stresses the fact that we are concerned with the interest earned on the portion of the project that is internally invested, not those portions that are released by (borrowed from) the project. To apply rate of return analysis correctly, we need to classify an investment into either a simple or a nonsimple investment. A simple investment is defined as one in which the initial cash flows are negative and only one sign change occurs in the net cash flow, whereas a nonsimple investment is one for which more than one sign change occurs in the net cash flow series. Multiple i*s occur only in nonsimple investments. However, not all nonsimple investments will have multiple i*s either.

23. For a simple investment, the solving rate of return (i*) is the rate of return internal to the project; so the decision rule is: If IRR > MARR, accept the project. If IRR = MARR, remain indifferent. If IRR < MARR, reject the project. IRR analysis yields results consistent with NPW and other equivalence methods. • For a nonsimple investment, because of the possibility of having multiple rates of return, we need to calculate the true IRR, or known as “return on invested capital.” However, your objective is to make an accept or reject decision, it is recommended the IRR analysis be abandoned and either the NPW or AE analysis be used to make an accept/reject decision. • When properly selecting among alternative projects by IRR analysis, incremental investment must be used.