Strategic Analysis and Planning is a field in which expertise and experience are key factors. In order to decide on strategic matters such as the competitive position of a company experts heavily lean on their ability to reason with uncertain or incomplete knowledge, or in other words on their experience and expertise. An important aspect is to assess a company's profit potential in the industry for which Porter's Competitive Forces Model is by far the most widely used framework. This article focuses on the various aspects of designing and developing an expert system representing Porter's Competitive Forces Model.