Michael Porter's five-force strategic analysis model, introduced in a 1979 article published in the Harvard Business Review, remains a fundamental tool for strategic analysts plotting the competitive landscape of an industry.

In a bid to mirror the complexity real strategists would face while keeping their strategic analysis manageable, Porter set out five forces at play in a given industry: internal competition, the potential for new entrants, the negotiating power of suppliers, the negotiating power of customers, and the ability of customers to find substitutes. Below, we take you through each of Porter's five forces, detail the significant critiques of his approach, and show how to apply the model to specific markets.