A new approach to evaluating alternatives under conditions of high environmental the certainty is to use the real-options theory. According to the real-options approach, when future is highly uncertain, it pays to have a broad range of options open. This is in contrast to using net present value (NPV to calculate the value of a project by predicting its payouts adjusting them for risk, and subtracting the amount invested. By boiling everything down to one scenario, NPV doesn't provide any flexibility in case circumstances change. NPV is als difficult to apply to projects in which the potential payoffs are currently unknown. The real options approach, however, deals with these issues by breaking the investment into stages