One common argument against the use of real options techniques is that they do not work when private risks dominate market risks. It is true that when the value of an investment is heavily dominated by private risks, the managers of the investing company have much less decision flexibility. In some sense, when the investment opportunity is driven by private risks (sometimes called unique risks or technical risks), the decisions are made by acts of God or other such phenomena over which the decision makers have no control. And, it is also true that when there is little flexibility, traditional techniques will provide an adequate way of estimating value. But, the point to keep in mind here is that private risks are treated the same whether you use real options or the old DCF approach. Only the market risks that are treated differently.