I got to know this competency as the one which gives me insight in the working process of the system inside a product. I learned that descriptive and mathematical models show you in what way different input values cause different output values.
It was surprising and useful to map the functions of a design into a model to see how the system inside would experience the action of the user and which input values would be created. On the other hand, I became aware of the experiences of the user upon the system and which reaction input values they create. The most important part I focused on this semester was this influence of User Focus and Perspective on this competency.
Moreover, I think creating these models is the possibility to get a first idea of the working of your product in the future. It is like imagining what users will do and how the product has to react. This enables you to have a small look on the working of your final design during the design process.
I did not really focus on the mathematical aspect of this competency, so I would like to discover this part in the next semester.