dea-r models and dea with ratio measure

Dea-r models and dea with ratio measure as a combination of dea and ratio analysis. in general, in the first category, standard dea models do not require modification to be able to calculate the exact amount of performance in the presence of ratio and absolute data. in the second category, there is no ratio exists, but the input-to-output ratios or vice versa are defined. therefore, using de models, the efficiency is calculated based on the defined ratios. these models behave similarly to dea models without explicit data.