Traditional accounting systems focus on the evaluation on tangible assets, neglecting the value addition contributed to business performance by intangibles. This paper explores the intangible evaluation concept and suggests a stock and flow based analysis to assess a methodology that could highlight static and dynamic aspects and their mutual impact on business performance. A general sketch, clarifying the numerous cause-effect relations among intangible assets, is provided to support the management in decision making. The aim of this methodology coincides with the main target pursued by firms: to get a competitive advantage or to maintain the already acquired leadership.