As implied earlier, perhaps the most common fantasy regarding UP adoption is that it is widely being applied in the iterative and adaptive manner its creators intended. Rather, a non-trivial percentage of organizations and consulting companies are incorrectly applying it in a predictive and waterfall spirit, with up-front specifications and planning.
Another fantasy is when the organization purchases many copies of the RUP product for their development staff, and continue with the mistaken belief that the presence of the installed product implies true iterative and evolutionary development is underway.
Another common and related fantasy is when the organization decides to adopt the RUP, thinking it is simply a more detailed, well-defined, and well-documented version of what they already expect in development (e.g., the waterfall), and they do not themselves have to make deep changes in their expectations and behavior. For example, in the RUP, reliable estimates for the entire project are not to be expected until the end of elaboration.
Instead, this happens: