Michael Porter developed the Five Forces model in the 1970s to analyze industry profitability. The model examines five competitive forces: threat of new entry, power of suppliers, power of buyers, threat of substitutes, and rivalry among existing competitors. Porter argued that by understanding these forces, companies can identify whether industries are attractive to compete in and determine appropriate strategies for improving profitability. The model helps explain why some industries are more profitable than others due to barriers that protect them from competition.