A well known trade-off effect with modelling is that when it is user friendly it becomes ambiguous and when it has a formal notation, that makes it unambiguous, it becomes less user friendly. A well known solution to this dilemma is to use models on various levels of formalism where the least formalized models are known to be more user friendly and the most formalized models are well suited for being directly translated to program code. This article investigates how the user friendliness at an informal level can be combined with the accuracy needed at a more formal level of modeling. It aims at combining an informal user friendly perspective with a formal developer perspective in order to minimize the time spent on transformation mapping between user friendly models and developer models. Theoretical data and empirical data indicates possibilities of minimizing the work with transformations between models. The results show that a number of developed criteria can be used to secure the user friendliness of models that are used in communications between the designer and the end user.