Once the Conceptual Design is complete, a revisit to the workplan is in order. More than likely, the original workplan estimates and assumptions were made based on broad, sweeping ideas that in many cases were a result of "gut" instincts. The workplan was probably adequate for getting the team to this point in the development process, however, much more valuable information is now available:
All of these facts can make significant contributions toward creating a revised workplan which illuminates the upcoming phases with increased accuracy and greater reliability. Therefore, re-estimation at this point is an important and sensible step which should not be overlooked.