Although IT has been converged with overall industries and has lead the improvement of productivity through improvement of systems, the construction industry has faced a limit in improvement of productivity due to adhesion of traditional methods. BIM was introduced to solve this issue, but BIM is not being currently applied due to lack of Planning Phase Collaboration because of segementation of work. Therefore, this study has purpose to review the applicability of exCPM methodology, which was suggested as a collaborative process modeling methodology in the industrial engineering field, in Architecture/Structure design process. By applying the exCPM methodology in processes deducted from actual case analysis, an Architecture/Structure collaborative process in Planning Phase is proposed. The proposed process was converted to the Petri-Nets model and analyzed to validate that the process model was properly established.