The difference and relationship of systems engineering and project management were discussed. It is concluded that the complex product development requirs the combination of systems engineering and project management. Therefore, a WBS (Work Breakdown Structure) model, PDA-WBS, is proposed to satisfy this requirement. The characteristic of the WBS is discussed, and a DWBS template which coordinates with the characteristic of the systems engineering is presented. Finally, a software framework to implementing the presented WBS is introduced.