Ranking decision-making units by imagined grey interval DEA model based on public weights

Based on public weights, an imagined grey interval DEA model is proposed to rank DMUs (decision-making units) with grey interval input and output variables. Weight vector which make the efficiency of ¿vitual DMU¿ achieves idea grey efficiency is treated as public weight vector. Input and output values of ¿vitual DMU¿ are equal to the average of all DMUs'. Further, efficiency of all DMUs is calculated based on public weight vector. To some extent, the proposed new method could be more fair and acceptable for all DMUs.