Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2007.3750.3755JahanshahlooG.R. AfzalinejadM. 122007723Data Envelopment Analysis (DEA) applies simple-structured linear programs to evaluate the efficiency of similar Decision Making Units (DMUs). For large-scale problems with a huge number of DMUs, however, it is a computationally expensive method. Since in large-scale problems the piece-wise linear frontier of the Production Possibility Set (PPS) tends to be a smooth nonlinear surface, it is reasonable to consider such a nonlinear frontier in efficiency evaluations. In this study, a parametric DEA method is proposed to estimate a quadratic frontier for the PPS in constant returns-to-scale environment. Quadratic frontiers better fit the reality of large-scale problems. In addition, parametric approaches reduce the computations to a great extent. With a numerical example, the proposed approach is compared with the CCR model, which shows that the results of the proposed approach are good approximations, even for small-size problems.]]>Ali, A.I.,1993646167Barr, R.S. and M.L. Durchholz,199773339372Bazaraa, M., J. Jarvis and H. Sherali, 1990Birman, S.V., P.E. Pirondi and E.Y. Rodin,200337923936Charnes, A., W.W. Cooper and E. Rhodes,19782429444Chen, Y. and A.I. Ali,2002142476479Dula, J.H. and R.V. Helgason,199692352367Dula, J.H., R.V. Helgason and N. Venugopal,199710323330Korhonen, P. and M. Halme,19965291300Thanassoulis, E.,1990