Porter's Five Forces Framework is a tool for analyzing competition of a business. It draws from industrial organization (IO) economics to derive five forces that determine the competitive intensity and, therefore, the attractiveness (or lack of it) of an industry in terms of its profitability. An "unattractive" industry is one in which the effect of these five forces reduces overall profitability. The most unattractive industry would be one approaching "pure competition", in which available profits for all firms are driven to normal profit levels (Wikipedia).
Profitable industries that yield high returns will attract new firms. New entrants eventually will decrease profitability for other firms in the industry. Unless the entry of new firms can be made more difficult by incumbents, abnormal profitability will fall towards zero (perfect competition), which is the minimum level of profitability required to keep an industry in business.
The following factors can have an effect on how much of a threat new entrants may pose:
A substitute product uses a different technology to try to solve the same economic need. Examples of substitutes are meat, poultry, and fish; landlines and cellular telephones; airlines, automobiles, trains, and ships; beer and wine; and so on. For example, tap water is a substitute for Coke, but Pepsi is a product that uses the same technology (albeit different ingredients) to compete head-to-head with Coke, so it is not a substitute. Increased marketing for drinking tap water might "shrink the pie" for both Coke and Pepsi, whereas increased Pepsi advertising would likely "grow the pie" (increase consumption of all soft drinks), while giving Pepsi a larger market share at Coke's expense.
The bargaining power of customers is also described as the market of outputs: the ability of customers to put the firm under pressure, which also affects the customer's sensitivity to price changes. Firms can take measures to reduce buyer power, such as implementing a loyalty program. Buyers' power is high if buyers have many alternatives. It is low if they have few choices.
The bargaining power of suppliers is also described as the market of inputs. Suppliers of raw materials, components, labor, and services (such as expertise) to the firm can be a source of power over the firm when there are few substitutes. If you are making biscuits and there is only one person who sells flour, you have no alternative but to buy it from them. Suppliers may refuse to work with the firm or charge excessively high prices for unique resources.
Potential factors are:
For most industries the intensity of competitive rivalry is the major determinant of the competitiveness of the industry. Having an understanding of industry rivals is vital to successfully market a product. Positioning pertains to how the public perceives a product and distinguishes it from competitors. A business must be aware of its competitors marketing strategy and pricing and also be reactive to any changes made.