With rapid growth of the world plant market, an increasing attention is paid on the plant engineering. Up to present time, Korean plant engineering technology has been concerned with the down stream part of the plant engineering, so called EPC, considered as a lower value chain compared with the up stream, composed of FEED(Front End Engineering Design) and PMC(Project Management Consultancy). In other words, a key issue for Korean plant industry is how to catch up the FEED technology, currently occupied by the advanced countries. In this paper, we propose an SE(Systems Engineering) approach, conventionally applied for aerospace and defense industry, to the FEED for plant engineering. Specifically, we proposed a new SE process composed of: 1) SPA matrix for reverse systems engineering, and 2) PPA matrix for forward systems engineering. To illustrate the proposed method, a case study for an environmental plant is performed.