Data reconciliation techniques are beginning to be widely applied in many different chemical and mineral beneficiation processes. However, a majority of the applications are for either single columns or a sequence of separation units. Efficient techniques have been proposed to solve data reconciliation problems of such bilinear processes. In this paper we compare two such methods (Crowe, C. M. AIChE J. 1986, 32, 616-623; Simpson, D. E.; Everett, M. G.; Voller, V. R. Appl. Math. Modelling 1988, 12, 204-212) on typical data from multicomponent industrial processes. Although Simpson’s method is shown to be more efficient and accurate, the need to generalize it further is pointed out.