In my opinion a combination should be used to analyze project.
If only a single tool is to be used, then Option3. Net Present Value using discount rate of company's WACC, is the best tool.
by
Muhammad qasim khan , Asst Financial Manager , Bukhatir education advancement and management
yes its better to use more than one method. but if you want to use1 method than internal rate of return(IRR) is better. as to calculate IRR one has to perform net present value calculation. through IRR you would exactly know what the project is returning you.
I would suggest that you use all methods. NPV is the most superior tool among the four that you listed, NPV helps you analyse the cashflows on the actual cost of capital to discount the cash flows when compared to IRR. IRR uses “arbitrary” rate and result is obtained by trial and error method.Payback is an easy to use tool which is good for premlinary analysis of the project.