1. A computer-implemented method performed by a computerized device, comprising: receiving a combinatorial testing model comprising an attribute collection, the attribute collection comprising a predetermined number of initial attributes, at least one possible value for each of the initial attributes, a coverage requirement, and an order coverage requirement for at least some of the initial attributes, the order coverage requirement related to predetermined relative order in which the values are to be applied to the initial attributes; providing at least two tests in which each of the initial attributes is assigned a value from the at least one possible value, wherein the at least two tests satisfy the order coverage requirement; determining permutations for the predetermined number and the coverage requirement; augmenting the initial attributes with at least one Boolean attribute, the at least one Boolean attribute associated with the order coverage requirement; mapping the permutations to values for the Boolean attributes; performing test design for the testing model with the at least one Boolean attribute, to obtain tests in which value combinations for the at least one Boolean attribute are selected in accordance with the values mapped from the permutations; and mapping the tests into values for the attributes, wherein the initial attributes are ordered in accordance with the values assigned to the at least one Boolean attribute.