This paper focuses on the predictions of ordering schemes in ternary B2 alloys based on the Nb–Ti–Al and Fe–Al–Ni systems, and comparing these results with those derived experimentally. The ordering tie-line (OTL) approach for depicting sublattice occupancies has been used as a basis for this comparison. Predictions of ordering schemes have been provided using a simple model based on classical Bragg–Williams theory of order–disorder transformations. Thus, OTLs have been calculated using a model based on an exchange reaction rate approach to predicting equilibrium properties. Experimentally, the OTLs have been determined by measurements of the apparent sublattice compositions using atom location by channeling enhanced microanalysis (ALCHEMI). It is shown that reasonably useful predictions may be obtained from the application of a simple thermodynamic model.