OMG’s Model Driven Architecture (MDA) proposes a computation independent view on the information system. It is used to specify the requirements and to describe how the system works within its environment. The key part of MDA is model transformation. Computation independent model (CIM) must be transformed to a platform independent model (PIM). The problem is that software development approaches that hold by MDA principles have informal models on CIM level. Without mathematical formalism, it is not possible to properly transform CIM to PIM. Topological Functioning Model for Software Engineering (TFM4SE) approach addresses this issue, and applies Topological Functioning Model (TFM) as a formal CIM. In this paper, TFM4SE is compared to approach that uses Business Process Model and Notation for CIM modeling. The comparison focuses on CIM modeling and on transformation to class diagram on PIM level. The results show what advantages and drawbacks does the formalism of TFM bring into the software development.