The presented research aims at modelling and formalising the process of team design activity as an interplay between the evolution of design problems and solutions. The motivation founds primarily on a presumption that there exist regularities in designing which can be captured and formalised using the appropriate models. The study thus investigates whether the identified design operation proportions and sequence probabilities are consistent throughout the different parts of team conceptual design activities. It does so by exploring the utility of mathematical models built based on the correlations and statistically significant sequences underlying the previously identified designing patterns. The developed mathematical model was tested by replicating moving-average analyses of design operation proportions and sequences, which were originally observed in the protocol analysis study. A close fit was found between the simulated and the observed data, particularly in providing insights regarding operation patterns and proportion trends. The presented models and modelling methodology are potentially an appropriate means for the next steps in describing, and consequently predicting and supporting team design activity dynamics.