Porter's generic strategies
Michael Porter has described a category scheme consisting of three general types of strategies that are commonly used by businesses to achieve and maintain competitive advantage. These three generic strategies are defined along two dimensions: strategic scope and strategic strength. Strategic scope is a demand-side dimension (Michael E. Porter was originally an engineer, then an economist before he specialized in strategy) and looks at the size and composition of the market you intend to target. Strategic strength is a supply-side dimension and looks at the strength or core competency of the firm. In particular he identified two competencies that he felt were most important: product differentiation and product cost (efficiency).
He originally ranked each of the three dimensions (level of differentiation, relative product cost, and scope of target market) as either low, medium, or high, and juxtaposed them in a three dimensional matrix. That is, the category scheme was displayed as a 3 by 3 by 3 cube. But most of the 27 combinations were not viable.
In his 1980 classic Competitive Strategy: Techniques for Analysing Industries and Competitors, Porter simplifies the scheme by reducing it down to the three best strategies. They are cost leadership, differentiation, and market segmentation (or focus). Market segmentation is narrow in scope while both cost leadership and differentiation are relatively broad in market scope.
Empirical research on the profit impact of marketing strategy indicated that firms with a high market share were often quite profitable, but so were many firms with low market share. The least profitable firms were those with moderate market share. This was sometimes referred to as the hole in the middle problem. Porter’s explanation of this is that firms with high market share were successful because they pursued a cost leadership strategy and firms with low market share were successful because they used market segmentation to focus on a small but profitable market niche. Firms in the middle were less profitable because they did not have a viable generic strategy.
Porter suggested combining multiple strategies is successful in only one case. Combining a market segmentation strategy with a product differentiation strategy was seen as an effective way of matching a firm’s product strategy (supply side) to the characteristics of your target market segments (demand side). But combinations like cost leadership with product differentiation were seen as hard (but not impossible) to implement due to the potential for conflict between cost minimization and the additional cost of value-added differentiation.
Since that time, empirical research has indicated companies pursuing both differentiation and low-cost strategies may be more successful than companies pursuing only one strategy.
Some commentators have made a distinction between cost leadership, that is, low cost strategies, and best cost strategies. They claim that a low cost strategy is rarely able to provide a sustainable competitive advantage. In most cases firms end up in price wars. Instead, they claim a best cost strategy is preferred. This involves providing the best value for a relatively low price.
Cost Leadership Strategy 
This strategy involves the firm winning market share by appealing to cost-conscious or price-sensitive customers. This is achieved by having the lowest prices in the target market segment, or at least the lowest price to value ratio (price compared to what customers receive). To succeed at offering the lowest price while still achieving profitability and a high return on investment, the firm must be able to operate at a lower cost than its rivals. There are three main ways to achieve this.
The first approach is achieving a high asset turnover. In service industries, this may mean for example a restaurant that turns tables around very quickly, or an airline that turns around flights very fast. In manufacturing, it will involve production of high volumes of output. These approaches mean fixed costs are spread over a larger number of units of the product or service, resulting in a lower unit cost, i.e. the firm hopes to take advantage of economies of scale and experience curve effects. For industrial firms, mass production becomes both a strategy and an end in itself. Higher levels of output both require and result in high market share, and create an entry barrier to potential competitors, who may be unable to achieve the scale necessary to match the firms low costs and prices.
The second dimension is achieving low direct and indirect operating costs. This is achieved by offering high volumes of standardized products, offering basic no-frills products and limiting customization and personalization of service. Production costs are kept low by using fewer components, using standard components, and limiting the number of models produced to ensure larger production runs. Overheads are kept low by paying low wages, locating premises in low rent areas, establishing a cost-conscious culture, etc. Maintaining this strategy requires a continuous search for cost reductions in all aspects of the business. This will include outsourcing, controlling production costs, increasing asset capacity utilization, and minimizing other costs including distribution, R&D and advertising. The associated distribution strategy is to obtain the most extensive distribution possible. Promotional strategy often involves trying to make a virtue out of low cost product features.
The third dimension is control over the supply/procurement chain to ensure low costs. This could be achieved by bulk buying to enjoy quantity discounts, squeezing suppliers on price, instituting competitive bidding for contracts, working with vendors to keep inventories low using methods such as Just-in-Time purchasing or Vendor-Managed Inventory. Wal-Mart is famous for squeezing its suppliers to ensure low prices for its goods. Dell Computer initially achieved market share by keeping inventories low and only building computers to order. Other procurement advantages could come from preferential access to raw materials, or backward integration.
Some writers assume that cost leadership strategies are only viable for large firms with the opportunity to enjoy economies of scale and large production volumes. However, this takes a limited industrial view of strategy. Small businesses can also be cost leaders if they enjoy any advantages conducive to low costs. For example, a local restaurant in a low rent location can attract price-sensitive customers if it offers a limited menu, rapid table turnover and employs staff on minimum wage. Innovation of products or processes may also enable a startup or small company to offer a cheaper product or service where incumbents' costs and prices have become too high. An example is the success of low-cost budget airlines who despite having fewer planes than the major airlines, were able to achieve market share growth by offering cheap, no-frills services at prices much cheaper than those of the larger incumbents.
A cost leadership strategy may have the disadvantage of lower customer loyalty, as price-sensitive customers will switch once a lower-priced substitute is available. A reputation as a cost leader may also result in a reputation for low quality, which may make it difficult for a firm to rebrand itself or its products if it chooses to shift to a differentiation strategy in future.
Differentiation Strategy 
Differentiate the products in some way in order to compete successfully. Examples of the successful use of a differentiation strategy are Hero Honda, Asian Paints, HLL, Nike athletic shoes, Perstorp BioProducts, Apple Computer, and Mercedes-Benz automobiles.
A differentiation strategy is appropriate where the target customer segment is not price-sensitive, the market is competitive or saturated, customers have very specific needs which are possibly under-served, and the firm has unique resources and capabilities which enable it to satisfy these needs in ways that are difficult to copy. These could include patents or other Intellectual Property (IP), unique technical expertise (e.g. Apple's design skills or Pixar's animation prowess), talented personnel (e.g. a sports team's star players or a brokerage firm's star traders), or innovative processes. Successful brand management also results in perceived uniqueness even when the physical product is the same as competitors. This way, Chiquita was able to brand bananas, Starbucks could brand coffee, and Nike could brand sneakers. Fashion brands rely heavily on this form of image differentiation.
Variants on the Differentiation Strategy 
The shareholder value model holds that the timing of the use of specialized knowledge can create a differentiation advantage as long as the knowledge remains unique. This model suggests that customers buy products or services from an organization to have access to its unique knowledge. The advantage is static, rather than dynamic, because the purchase is a one-time event.
The unlimited resources model utilizes a large base of resources that allows an organization to outlast competitors by practicing a differentiation strategy. An organization with greater resources can manage risk and sustain profits more easily than one with fewer resources. This provides a short-term advantage only. If a firm lacks the capacity for continual innovation, it will not sustain its competitive position over time.
Focus or Strategic Scope 
This dimension is not a separate strategy per se, but describes the scope over which the company should compete based on cost leadership or differentiation. The firm can choose to compete in the mass market (like Wal-Mart) with a broad scope, or in a defined, focused market segment with a narrow scope. In either case, the basis of competition will still be either cost leadership or differentiation.
In adopting a narrow focus, the company ideally focuses on a few target markets (also called a segmentation strategy or niche strategy). These should be distinct groups with specialized needs. The choice of offering low prices or differentiated products/services should depend on the needs of the selected segment and the resources and capabilities of the firm. It is hoped that by focusing your marketing efforts on one or two narrow market segments and tailoring your marketing mix to these specialized markets, you can better meet the needs of that target market. The firm typically looks to gain a competitive advantage through product innovation and/or brand marketing rather than efficiency. It is most suitable for relatively small firms but can be used by any company. A focused strategy should target market segments that are less vulnerable to substitutes or where a competition is weakest to earn above-average return on investment.
Examples of firm using a focus strategy include Southwest Airlines, which provides short-haul point-to-point flights in contrast to the hub-and-spoke model of mainstream carriers, and Family Dollar.
In adopting a broad focus scope, the principle is the same: the firm must ascertain the needs and wants of the mass market, and compete either on price (low cost) or differentiation (quality, brand and customization) depending on its resources and capabilities. Wal Mart has a broad scope and adopts a cost leadership strategy in the mass market. Pixar also targets the mass market with its movies, but adopts a differentiation strategy, using its unique capabilities in story-telling and animation to produce signature animated movies that are hard to copy, and for which customers are willing to pay to see and own. Apple also targets the mass market with its iPhone and iPod products, but combines this broad scope with a differentiation strategy based on design, branding and user experience that enables it to charge a price premium due to the perceived unavailability of close substitutes.
Recent developments 
Michael Treacy and Fred Wiersema (1993) in their book The Discipline of Market Leaders have modified Porter's three strategies to describe three basic "value disciplines" that can create customer value and provide a competitive advantage. They are operational excellence, product leadership, and customer intimacy.
A popular post-Porter model was presented by W. Chan Kim and Renée Mauborgne in their 1999 Harvard Business Review article "Creating New Market Space". In this article they described a "value innovation" model in which companies must look outside their present paradigms to find new value propositions. Their approach complements most of Porter's thinking, especially the concept of differentiation. They later went on to publish their ideas in the book Blue Ocean Strategy. Thus it is difficult, but not impossible, to topple a firm that has established a dominant standard.
Criticisms of generic strategies 
Several commentators have questioned the use of generic strategies claiming they lack specificity, lack flexibility, and are limiting.
Porter stressed the idea that only one strategy should be adopted by a firm and failure to do so will result in “stuck in the middle” scenario. He discussed the idea that practising more than one strategy will lose the entire focus of the organization hence clear direction of the future trajectory could not be established. The argument is based on the fundamental that differentiation will incur costs to the firm which clearly contradicts with the basis of low cost strategy and on the other hand relatively standardised products with features acceptable to many customers will not carry any differentiation hence, cost leadership and differentiation strategy will be mutually exclusive. Two focal objectives of low cost leadership and differentiation clash with each other resulting in no proper direction for a firm. In particular, Miller questions the notion of being "caught in the middle". He claims that there is a viable middle ground between strategies. Many companies, for example, have entered a market as a niche player and gradually expanded. According to Baden-Fuller and Stopford (1992) the most successful companies are the ones that can resolve what they call "the dilemma of opposites".
However, contrarily to the rationalisation of Porter, contemporary research has shown evidence of successful firms practising such a “hybrid strategy”. Research writings of Davis (1984 cited by Prajogo 2007, p. 74) state that firms employing the hybrid business strategy (Low cost and differentiation strategy) outperform the ones adopting one generic strategy. Sharing the same view point, Hill (1988 cited by Akan et al. 2006, p. 49) challenged Porter’s concept regarding mutual exclusivity of low cost and differentiation strategy and further argued that successful combination of those two strategies will result in sustainable competitive advantage. As to Wright and other (1990 cited by Akan et al. 2006, p. 50) multiple business strategies are required to respond effectively to any environment condition. In the mid to late 1980s where the environments were relatively stable there was no requirement for flexibility in business strategies but survival in the rapidly changing, highly unpredictable present market contexts will require flexibility to face any contingency (Anderson 1997, Goldman et al. 1995, Pine 1993 cited by Radas 2005, p. 197). After eleven years Porter revised his thinking and accepted the fact that hybrid business strategy could exist (Porter cited by Projogo 2007, p. 70) and writes in the following manner.
Though Porter had a fundamental rationalisation in his concept about the invalidity of hybrid business strategy, the highly volatile and turbulent market conditions will not permit survival of rigid business strategies since long term establishment will depend on the agility and the quick responsiveness towards market and environmental conditions. Market and environmental turbulence will make drastic implications on the root establishment of a firm. If a firm’s business strategy could not cope with the environmental and market contingencies, long term survival becomes unrealistic. Diverging the strategy into different avenues with the view to exploit opportunities and avoid threats created by market conditions will be a pragmatic approach for a firm. Critical analysis done separately for cost leadership strategy and differentiation strategy identifies elementary value in both strategies in creating and sustaining a competitive advantage. Consistent and superior performance than competition could be reached with stronger foundations in the event “hybrid strategy” is adopted. Depending on the market and competitive conditions hybrid strategy should be adjusted regarding the extent which each generic strategy (cost leadership or differentiation) should be given priority in practice.
See also 
- Critique of generic strategies and their limitations, including Porter - "Generic strategies: a substitute for thinking?"
- Wright, Peter, Kroll, Mark, Kedia, Ben, and Pringle, Charles. 1990. Strategic Profiles, Market Share, and Business Performance. Industrial Management, May 1, pp23-28.
- William E. Fruhan, Jr., "The NPV Model of Strategy—The Shareholder Value Model," in Financial Strategy: Studies in the Creation, Transfer, and Destruction of Shareholder Value (Homewood, IL: Richard D. Irwin, 1979)
- Porter, M.E., "Competitive Strategy: Techniques for analyzing industries and competitors" New York: The Free Press (1980)
- Panayides, "Unknown" (2003)
- Miller, D., "The generic strategy trap" in The Journal of Business Strategy 13(1):37-41 1992)
- Hambrick, D, "An empirical typology of mature industrial product environments" Academy of Management Journal, 26: 213-230. (1983)
- Murray, A.I. "A contingency view of Porter's "generic strategies." Academy of Management Review, 13: 390-400. (1988)
- Wright, P, "A refinement of Porter's strategies." Strategic Management Journal, 8: 93-101.(1987)