پاورپوینت درمورد تجزیه و تحلیل اقتصادی مهندسی
Engineering Economic Analysis
Time Value of Money
Internal Rate of Return
Internal rate of return
Access to Capital
Present Value and Future Value Calculations (discounted cash flows)
Present value is the value in today’s dollars assigned to an amount of money in the future, based on some estimate rate-of-return over the long-term. In this analysis, rate-of-return is calculated based on monthly compounding.
Two cases of present value are discussed next. Case 1 involves a single sum that stays invested over time. Case 2 involves a cash stream that is paid regularly over time (e.g., rent payments), and requires that you also calculate the effects of inflation.
Case 1a: Present value of money invested over time.
This tells you what a future sum is worth today, given some rate of return over the time between now and the future. Another way to read this is that you must invest the present value today at the rate-of-return to have some future sum in some years from now (but this only considers the raw dollars, not the purchasing power).
To compute the present value of an invested sum, the formula for interest that is compounded monthly is:
pv = ——————————
(۱ + rrate/12) ** (12 * termy)
* future-sum = dollar value you want to have in termy years
* termy = term, in years
* rrate = annual rate of return that you can expect, in decimal
I need to have 10,000 in 5 years. The present value of 10,000 assuming an 8% monthly compounded rate-of-return is 6712.10. I.e., 6712 will grow to 10k in 5 years at 8%.
Case 1b: Effects of inflation
This formulation can also be used to estimate the effects of inflation; i.e., compute the real purchasing power of present and future sums. Simply use an estimated rate of inflation instead of a rate of return for the rrate