BIM, is it prototyping or documentation?

There seems to be a fundamental challenge in the conflicting goals of the development of virtual prototypes (which are developed for design and decision making), and final virtual models which are developed for documentation of design decisions. The challenge is to identify the appropriate time to move from prototypes to digital model. Any potential information reuse between the prototyping process and the digital model can be valuable, particularly if it makes the prototyping process more efficient.