. Oxford Company’s opportunities for reinvesting funds as they are released from a project will determine which ranking is best. The internal rate of return method assumes that any released funds are reinvested at the rate of return shown for a project. This means that funds released from project D would have to be reinvested in another project yielding a rate of return of 22%. Another project yielding such a high rate of return might be difficult to find.
The project profitability index approach also assumes that funds released from a project are reinvested in other projects. But the assumption is that the return earned by these other projects is equal to the discount rate, which in this case is only 10%. On balance, the project profitability index is generally regarded as being the most dependable method of ranking competing projects.
The net present value is inferior to the project profitability index as a ranking device, because it looks only at the total amount of net present value from a project and does not consider the amount of investment required. For example, it ranks project C as fourth because of its low net present value; yet this project is the best available in terms of the net present value generated for each dollar of investment (as shown by the project profitability index).