The Business Process Model represented as a diagram in Business Process Modeling Notation (BPMN) is a commonly used way how to describe business processes of an organization. Problems connected with a complexity of notation and missing support in tools for the software development can be solved by a transformation to a Unified Modeling Language activity diagram. Another reason for creating such a kind of transformation is that it can solve problems of time, cost and quality associated with software creation in the scope of Model Driven Development. This article describes common problems with the transformation of a BPMN diagram to a Unified Modeling Language activity diagram. One of the key features of the described transformation is that it is tool independent. This feature was achieved by using an XML metadata interchange representation of both models as an input and output and by using XSLT transformation for the model transformation itself.