Hi Bill, we've learnt that there are two many methods in regards to projects which I think you are talking about as general flexibility in finance is a very broad topic!
Real Options Analysis - ROA uses models like bespoke simulation and binomial to estimate the vale of the contingent. It is most commonly used when the value of the project depends on the value of another asset (or variable).
Decision Tree Analysis - The simplest method that maps our the different choices that the decision makers have in taking the business. This method looks at the different events that could occur and the decisions required to tackle them, which in turn leads to being able to value flexibility.