Now problems of a multi-criteria quality estimation of models as well as a justified selection of task-oriented models are still not investigated thoroughly enough. The importance of the problems increaseswhen a research object is described not via a single model, but with a set or a complex of multiple mod-els including models from different classes or combined models such as combined analytical-simulationmodels, logical-algebraic ones, etc. The aforementioned problems are being investigated within the the-ory of model quality control. The description of main elements of this theory and its applications is theprimary goal of the paper.