Title: A Tchebycheff DEA model Authors: 1) Gabriel Tavares 2) Carlos Henggeler Antunes Abstract: In this study a new Data Envelopment Analysis (DEA) model is proposed that minimizes the Loo (or Tchebycheff) distance of each Decision Making Unit (DMU) to the efficient frontier. This model is obtained by using the same constraints of the additive model but with a different objective function. -This function is based on the LĄ metric and, contrary to the additive model, relies on the minimization of the distance of the actual operation point to the observed extreme frontier. This last issue is important since a better efficiency evaluation can be achieved with this model with respect to the additive model. The conditions in which the normal (instead of the augmented) Tchebycheff distance could be used to guarantee the attainment of efficient solutions are shown. Simple graphical examples (in 2D and 3D) are used to illustrate the proposed DEA model.