The Financial and Planning Department at Weston Steel had an internal meeting regarding the capital investment for its recent expansion project . There is a debate over the various investment evaluation methods . Which one the following statement is incorrect ? Projects with unconventional cash flows will have multiple internal rates of return ( IRR ) solutions . It is problematic to use this method even if one solution is larger than the company's co of capital Profitability Index ( Pl ) generally leads to identical decision to net present value ( NPV ) method except under the situation where company has hard capital rationing . Accounting average return does not use project cash flows and the average book value of the assets is subject to the choice of depreciation methods easy to communicate with the payback period which considers both the timing and amount of a project's all cash flows .