Comparison of alternative decision criteria There are four principal decision models for evaluating and selecting investment projects: There are four principal decision models for evaluating and selecting investment projects: - Net present value (NPV) - Profitability index (PI) - Internal rate of return (IRR) - Payback period (PB) Which criteria assume that the project's net cash flows (NCFs) are reinvested at the project's internal rate of return? IRR and PI IRR NPV and PI Conventional PB.