The process itself has two serious drawbacks. First, project teams generally know how good the projections (such as NPV) need to look in order to win funding, and it takes only nanoseconds to tweak an assumption and run another full scenario to get a faltering project over the hurdle rate. If, as is often the case, there are eight to 10 assumptions underpinning the financial model, changing only a few of them by a mere 2% or 3% each may do the trick. It is then difficult for the senior managers who sit as gatekeepers to even discern which are the salient assumptions, let alone judge whether they are realistic.