引言

在當今的世界經濟下，對國際企業來說運用他們的相對優勢來保持競爭力和成功的現狀是非常重要的。貿易應當根據企業的競爭劣勢來適當的利用他們的戰略方案（加斯馬丁，2001）。通常來說，任何戰略方案的主要的目的都是維持他們在競爭方面的優勢，這樣就能更好的在產量和利潤上取得更好的效果。為了能夠獲得競爭的優勢，所有層面的戰略方案，不管是哪一個策略水平，運用策略來讓一個企業獲得競爭方面的優勢，都應該將各部分的功能區分開來（希爾，瓊斯，2007）。這是波特模型中最關鍵的一個方面。

本文將論證在國際環境中的波特法，發展有效的競爭戰略將會給國際企業的活動帶來更多的可能性和更高的效率。本文將分成三個部分。第一部分，利用波特模型詳細分析競爭策略在國際商貿中的影響。在第二部分，將會解釋價值鏈對于保持競爭力的作用。第三部分，將論述競爭優勢的持續性。最后是總結。

Introduction

In the current global economy, it has become essential for international business to use their comparative advantages to become or continue competitive and successful. Business should enhance the use of their strategy in light of their competitive disadvantages (Jasimuddin, 2001).Generally, the main aim of any strategy is to get a sustained competitive advantage, which result in greater productivity and profitability. In making a competitive advantage all levels of strategy are involved. Regardless of what the strategy level , to use strategy to get a competitive advantage a company should make distinguishing capabilities (Hill & Jones, 2007). This is the key aspect of Porter's model.

This essay will argue that Porter's approach will give international business activities more possible and efficient within the international field through developing an effective competitive strategy. The essay will be divided to three main parts. In the first part, achieving competitive strategy in intentional business by applying Porter Model will be discussed in detail. In the second part, the effect of the value chain in sustaining competiveness will be explained. In the third part, Sustainability of competitive advantage will be argued. Finally, the conclusion will be draw from this discussion.

Achieving competitive strategy in intentional business

The competitive advantage, as Porter (2004) argued, counts on choosing the suitable generic strategy to achieve business goals in the circumstance of the competitive environment (Porter, 2004). There are three types of generic strategy that a companies use to expand and maintain competitive advantage: cost leadership, differentiation and focus (Stonehouse et al, 2004).

1-Cost leadership strategy

Within an industry, an organization that implies a cost leadership strategy, tries to be the lowest cost producer (Stonehouse et al, 2004) . To increase sales the cost leadership strategy charge a price similar or lower than competitors in an industry, so the main endeavor is to earn a higher profit because unit costs are lower. This strategy will be a success and bring rise in sales proportions due to the high demand for the products and to some extent the lower prices compare to competitors (Porter, 2004).

This kind of strategy has two major advantages: first, they will have the opportunity to make profits higher than the industry average by fee a price similar with the average for the industry, second, this price strategy help business to compete efficiently in the industry with existence competitor and potential new entrance (Stonehouse et al, 2004) . Firms which are trying to entering a new market they usually used such strategy. For example, some of the major Japanese car and motorcycle manufacturers initially entered overseas markets on the basis of low-cost and low-price strategies (Stonehouse et al, 2004).

2- Differentiation

A differentiation strategy means that the organizations present for the customers unique products and appreciated then other competitors. Differentiation ,as Porter(1985) argued, present a low price with unique products, for that the companies earn the customers faithfulness or loyalty. For this reason customers spent more for what they consider superior products, as a result of, the differentiation strategy more advantage than the cost leaderships strategy (Boddy et al, 2005) . For example , in the case of Nokia they were able to achieve differentiation by their products unique design , where Sony electronics reach differentiation by present better dependability, service and technology. Also BMW achieve differentiation through the unique product and service image, whereas Coca-Cale reach it by distinguished brand world-wide. From all these examples we can notice that usually a lot expenditure on advertising and promotion required in this strategy to maintain the brand identity (Boddy et al, 2005).

3- Focus strategy

Usually, focus strategy choose to aim specific segments of the market in which they operate ,this can involve focusing on specific consumers group in the market (Stonehouse et al, 2004). Focus strategy ,according to Porter (2004, pp.15)," based on identification of a market segment with distinct characteristics and selecting a strategy that matches those characteristics." There are twofold for strategy derived from segmentation: first, focus(on a single segment), second, multifocus (focus on a number of segment) (Porter, 2004). As Stonehouse et al. (2004, pp. 177-178 ) indicated that " to compete with other companies within the chosen market segment, businesses may employ a cost focus strategy that is essentially cost leadership confined to one market segment. Alternatively, they may utilize a differentiation focus strategy whereby they seek to differentiate themselves and their product from other product within the chosen market segment."

As any theory, Porter's theory have been criticizes by other researchers. One of the main disparagement was against his argument that a company had to select from the two strategy either cost leadership or differentiation. It was argues that a company can follow both strategies at the same time by controlling costs better than competitors, companies can reinvest the saving in features that differentiate the product or service. Several commentators have questioned the use of generic strategies claiming they lack specificity, lack flexibility, and are limiting. In particular, Miller (1992) 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. However , Porter(1998) presented some explanation: 'Every strategy must consider both relative cost and relative differentiation... a company cannot completely ignore quality and differentiation in the pursuit of cost advantage, and vice versa....Progress can be made against both types of advantage simultaneously' (p.271). However, he observations there are trade- offs between the two and that f should 'maintain a clear commitment to superiority in one of them' (Porter,1998). Although Porter's work has been criticized it is still a vary widely used model of competitive behavior.

The value chain and competitive advantage

As companies are encounter with slower increase and stronger rivalry, competitive advantage becomes important to the maintenance of superior performance. Competitive advantage develop essentially out of the value a company is able to make for its buyers. In competitive conditions, value is the quantity which buyers are ready to pay from what a company offer to them. Porter uses the theory of a value chain to divided buyers, suppliers and a company into the separate but related activities from which value stem. Such a process is required to understand the behavior of costs and the basis of differentiation (Porter, 1985).

A company's value chain fall into nine generic activities which are connected to each other and to the activities of its suppliers, channels and buyers. They can be divided into two broad types: primary activities, which involve in the physical creation of the product, its marketing and delivery to the buyers, and its support and servicing after sales; and support activities, which provide the inputs, technology, human resources, and infrastructure that allow the primary activities to take place. It is required to separate activities with isolated technologies and economics to analyze a company's competitive advantage. Broad function should be divided into activities, such as manufacturing or marketing. A company does must be captured in a primary or support activity, a process which often needs some degree of judgment. Comparing the value chains of competitors then highlights differences which form the basis of competitive advantage (Porter, 1985).

'However, while discrete value activities are the building blocks of competitive advantage, they are not independent. They are related by linkages within the chain which reflect relationships between the way one value activity is performed and the cost or performance of another. Linkages within the value chain are crucial for competitive advantage, but are often subtle and go unrecognized. Exploiting linkages usually requires information flows that allow optimization or coordination to take place. Linkages not only exist within a firm's value chain, but between a firm's chain and the value chains of suppliers and channels (vertical linkages), thus providing additional opportunities to enhance competitive advantage. By highlighting the role of these vertical linkages, the value chain approach also allows a firm to identify more clearly the potential benefits of integration' (Porter, 1985).

Buyers also have value chains, and a company's differentiation stops from how its value chain relates to its buyer's chain. Spots of contact between buyers and the company are possible sources of competitive advantage, where value for the buyer (in the form of lower costs or improved performance) is created through a firm's impact on the buyer's value chain (Porter, 1985).

'The competitive scope of a firm is also important in creating competitive advantage.

Broad scope, for example, may allow a firm to exploit interrelationships between the value chains that serve a number of different product or buyer segments, geographic areas or related industries, while narrow scope can allow the tailoring of its chain to serve a particular target segment, geographic area or industry, resulting in lower costs or differentiation compared to competitors. This relationship between competitive scope and the value chain provides the basis for defining more relevant business unit boundaries and allows a firm to establish organizational structure more in line with its sources of competitive advantage' (Porter, 1985).

Sustainability of competitive advantage

Reaching competitive advantage is not only the aim of any business strategy , the main goal of any organization is the sustainability's for this competitive advantages as long as possible. This include two things: first, that this strategy will guide to great performance in an industry: and second, that great performance can be sustained over time not for just short period (Porter, 2004). The extent to which competitive advantage is sustainable will usually depend on a number of organizational aspects: it will depend in developing a strategies that are superior to those of competitors and that are difficult to emulate; it will depend in its ability to continuously innovate and improve strategies; it will depend in the competitors lack of ability to imitate their business, finally, it will depend on change in the business environment, like technological change, which may be beyond the control of the leading competitor and which may enhance or reduce its competitive advantage (Stonehouse et a, 2004.).

It is important to realize that if a company gains a competitive advantage through a new way of doing things or better way of doing old thing, this competitive advantage must be both feasible and sustainable over time. For example, American Airlines was the originator and controller of the world's largest computer reservation system, the SABRE Semi-automated Business Research Environment system. This achievement put America at or near the top of the most list of successful example of how to gain competitive advantage among rivals (Hopper, 1990). In 1973 alone, American Airlines lost $50 million on revenue of $1.3 billion. In the early 1970s, American Airlines operated at a loss. Operating at a loss, it found itself in great danger. It began to lose the patronage of its frequent customers, particularly business clients. New airline companies were attempting to compete with major airlines such as TWA and American by introducing low-ticket fares, which American could not match without losing profit. In addition, the Competitors hired labor at much lower cost. By the mid-1970s, American Airlines had developed computer reservation systems, SABRE, which help the airline overcome its major problems (Copeland, 1988) . American's SABRE system was the world's first computer reservation system. It was a accomplishment for a number of reasons. Buyers received faster, one-stop shopping for flights and other travel accommodations. It extended service and improved the efficiency of travel agents. It resulted in cost reduction of airline administration expenses and it also provides a marketing method that was significant over time. Most important is that SABRE was core system that becomes a completely integrated approach to managing a very complex business. SABRE helped changing rules according on the attitudes, priorities and preferences of the customer (Callon, 1996). SABRE linked in many travel agents around the country. The data communications from the travel agents to the hosts were based on dial up internet-like communication. The SABRE system served as the principal distribution network for flight schedules. In the schedule displays, each flight listing is a type of electronic shelf. SABRE lists codes for requesting information about origination and destination, flight time, departure and arrival time, and so forth. In order to build the system, from 1976 to 1982, American Airlines had invested approximately $114 million in hardware plus another $46 million in expansion of central site facilities and equipment. The result was a dramatic transformation of airline ticket distribution methods (Laudon , 2005).

Conclusion

Porter suggests three 'generic' competitive strategies to do better than other companies in a particular industry which these are cost leadership, differentiation and focus. A cost leader is a company which can produce a similar product more professionally than its competitors. Differentiation happen when a company can produce unique products which earn loyalty from the customer in terms of quality, features and price. In addition, when lower-cost or differentiation strategies are focused on a market niche, they are called cost focus and focused differentiation and Each of these different strategies has its advantages and disadvantages. A company needs to manage its strategy all the time; otherwise it risks being 'stuck in the middle'. To summarize, these days every company must understand the broad affects of impaling effectual strategy that can make sustainable competitive advantage. Competitive strategy aim to establish a profitable and sustainable position against the forces that decide industry competition. Competition is at the core if the success or failure of company.