This essay, prepared for Holmes Institute's HI6006 Competitive Strategy course, provides a comprehensive discussion of three essential strategy development tools. It begins with an overview of the Porter's Five Forces model, detailing its application in analyzing the microenvironment and competitive forces faced by businesses, using Woolworths as an example. The essay then explores SWOT analysis, emphasizing its role in assessing internal strengths and weaknesses alongside external opportunities and threats, with a case study of ANZ Bank. Finally, the PESTEL analysis model is examined, focusing on its utility in evaluating the macro-environment and its impact on strategic decisions, with Wesfarmers as a practical example. The essay concludes by summarizing the importance of these frameworks in developing effective organizational strategies and achieving business goals.