Porter's Five Forces Model of competition (Porter, 1980), defines the competitive space of a business enterprise as being comprises of five forces --

• new entrants -- with the threat of new entrants entry barriers
• suppliers -- with the bargaining power of suppliers and factors of supplier power
• substitutes -- the threat of substitutes
• buyers -- with the bargaining power of buyers and their leverage and sensitivity to price
• rivals -- addressing the intensity of rivalry from direct competitors