This paper explores the use of scenario planning and the design of a knowledge-based system in strategic decision making, in the context of the European airline industry. Several innovative strategies were derived, as well as other key recommendations based on sound strategic reasoning, and participants testified to the effectiveness of the approach in stretching their thinking. The requirement to draft strategies as expert system rules, with reasons, was useful in clarifying thinking and achieving group consensus. This methodology, therefore, aids effectiveness of the scenario planning process itself, while providing a dynamic, accessible means of storing the resulting strategic thinking.