One drawback of the payback method is that this method does not consider cash flows that occur beyond the payback period. The shorter a project's payback period, the less desirable the project is normally considered to be by this criterion The regular payback ignores cash flows beyond the payback period, but the discounted payback method overcomes this problem. If a project's payback is a positive number, then the project should be accepted because it must have a positive NPV