This essay provides a detailed analysis of three key strategy development tools: PESTEL, SWOT, and Porter's Five Forces. It explains each model's components and how they are used to assess a company's internal and external environment. The PESTEL analysis covers political, economic, social, technological, environmental, and legal factors affecting businesses. The SWOT analysis focuses on a company's strengths, weaknesses, opportunities, and threats. Porter's Five Forces model examines the competitive intensity and attractiveness of an industry. The essay includes practical applications of these models with examples like Nike, Microsoft and MacDonald to illustrate their use in real-world business scenarios. The analysis aims to provide a comprehensive understanding of these strategic tools for effective decision-making and competitive advantage.