Small and medium enterprises (SME) is one type of business that an important role for the indonesian economy. where's presence can help in economic growth and create employment which is currently more difficult to obtain. every SME should be able to build a competitive advantage of SMEs is one of managers. to identify how be behavior of managers in building competitive advantage writer doing research on the behavior of the manager of a SME SME Restu ibu, in this study the author using soft system methodology as an approach to system with application programs assited soft systems methodology is a writer for the microsoft visual basic 6.0, the where this application is used to facililate the processing of data. while research method used was grounded theory based on ten roles managers (mintzberg,1975) with data collection techniques literature study, observation and interviews. strategic behavior model to determine a strategy, implement behavioral models of production, model of behavior and conduct research to innovate, the model determines the place and carry out marketting and behavioral model of cooperation with parties other. the sixth model is the behavior of a model of strategic behavior of managers in building competitive advantage.