Despite the widespread use of technology and information technology in health care there are many problems and flaws registered by several studies, due mainly to the lack of consideration of human factors in its development and implementation. Technology in health care must be based on users and organizations needs, besides the centered concern with its technological power. To accomplish that purpose healthcare must, at first, be aware of their real needs because this context has still a significant lack of knowledge of their complexity. The basis to achieve that objective is the analysis of work system as well as the consideration of usability principles in technology that will permit a better interaction, rendering the system more efficient and safe. The present study is an example of a work system analysis in a pediatric cardiac surgery room.