Systems Thinking is a way to interpret and understand the phenomena, which differs from the conventional way called reductionist where understanding is not done through the decomposition of the parties, but is performed with emphasis on understanding the system as a whole and the interrelationships that emerge from the system and therefore the interpretation is not given from an analysis of cause and effect, but an understanding of the system within the context of a higher whole. This research is performed by applying Systems Thinking in a practical case of an organization such as Engativá Hospital, interpreting the organization from the systemic point of view and producing a causal diagram that allows to read of the organization from this point of view. A model was developed into a tool for system dynamics, the design and simulation is limited to the Credit Portfolio Process - Cashing and Collection Management, doing a reading and interpretation of results and the findings produced by the model. Finally is concluded that it is factible to run an organization from the Systems Thinking and it improves the decision making.