This paper describes multi-objective evolutionary optimization of process planning in flexible manufacturing systems (FMSs). FMS can be described as an integrated manufacturing system consisting of machines, computers, robots, and automated guided vehicles (AGVs). While FMSs give great advantages through the flexibility, FMSs pose complex problems on multi-objective process planning. An evolutionary approach using a multi-objective evolutionary algorithm with a new elite clearing mechanism is proposed for solving the multi-objective process planning problems (MOPPPs). The experimental results demonstrate that our algorithm can solve MOPPPs efficiently.