In the last three decades, the business processes are considered as key terms and often discussed in scientific literature dealing with management and organization. The role the business processes have in making companies more successful has been recognized in practice, and thus the increasing number of organizations transforms from functional ones to process-oriented ones. In order for a business process to be successful, certain criteria have to be met: it has to be consumer-oriented, create added value, have a capable owner, be easily understood by all participants, who should also be included in the decision-making process, efficiency and success of the process should be measured regularly, and the process itself should be improved regularly. Business processes should be defined in such a way that the employees can understand their roles, responsibilities, dependence and how the work is done. If the business processes are described only textually, then it is considered a statistical approach to documenting, but if the business processes are presented by using both graphical presentation and text, then it is called a dynamic approach (which is also called business process modeling). The newest and presently the most widely used norm for determining the way in which the processes are presented and described is called BPMN, Business Process Modeling and Notation. BPMN is a formal language, composed of a number of graphical and logical symbols with firmly defined semantics, and it is used for modeling the business processes. This paper analyzes the business process by using the example of gas supplier change. By using the BPMN 2.0 norm, the business processes are presented by collaboration diagrams. The process of gas supplier change has improved significantly with the introduction of information system, which also affected the business processes related to the process of gas supplier change. By comparing the diagrams before and after introducing the information system, we conclude that the supplier change is now simpler, faster and more efficient. Consequently, it resulted in favorable preconditions for the end users to fill in the forms with minimal efforts. Thus, the ultimate goal of every business process is realized, and that is the satisfaction of the end user.