In an effort to discriminate the performance of efficient decision making units (DMUs), the concept of super-efficiency is proposed, whose basic idea is to eliminate the DMU under evaluation from the reference set. When applied to the variable returns to scale (VRS) situation, the resulting super-efficiency model may become infeasible for certain DMUs due to the convexity constraint. Infeasibility restricts a wider use of super-efficiency DEA. Therefore, taking different viewpoints, a significant amount of studies tackle this problem by developing various new VRS super-efficiency models.