  This paper presents discussions on the limitations of the witness
configuration method. These limitations have rarely been reported in previous
studies. The witness configuration method is a very recent approach for
geometric constraint solving, which is of critical importance for modern
computer-aided design systems. The witness configuration method may be the most
promising method to solve satisfactorily the challenges of geometric constraint
solving. This method, in the current form, is however found to be limited for
the three essential tasks in the geometric constraint solving domain. Examples
are given to validate this work's statements on these limitations.
