波特五力模型是邁克爾•波特（Michael Porter）于20世紀(jì)80年代初提出，它認(rèn)為行業(yè)中存在著決定競(jìng)爭(zhēng)規(guī)模和程度的五種力量，這五種力量綜合起來(lái)影響著產(chǎn)業(yè)的吸引力以及現(xiàn)有企業(yè)的競(jìng)爭(zhēng)戰(zhàn)略決策。五種力量分別為同行業(yè)內(nèi)現(xiàn)有競(jìng)爭(zhēng)者的競(jìng)爭(zhēng)能力、潛在競(jìng)爭(zhēng)者進(jìn)入的能力、替代品的替代能力、供應(yīng)商的討價(jià)還價(jià)能力、購(gòu)買者的討價(jià)還價(jià)能力。

Porter's five forces model focuses on the competitive nature of an industry and therefore attractiveness of a market.

Attractiveness in this context refers to the overall industry profitability. They consist of forces which affect a company's ability to serve its customers and make a profit. A change in any of these forces normally would require a company to reassess the marketplace.

Porter claimed that there are five "competitive forces" affecting every industry and that, in most, some force other than rivalry has the greatest impact on the levels of margin earned:

? The threat of new entrants to the industry;

? The threat of substitute products or services;

? The bargaining power of suppliers;

? The bargaining power of customers; and

? The rivalry among current competitors in the industry.

關(guān)于五力分析模型的實(shí)踐運(yùn)用一直存在許多爭(zhēng)論。較為一致的看法是：該模型更多是一種理論思考工具，而非可以實(shí)際操作的戰(zhàn)略工具。該模型的理論是建立在以下三個(gè)假定基礎(chǔ)之上的：

1、制定戰(zhàn)略者需要了解整個(gè)行業(yè)的信息，顯然現(xiàn)實(shí)中是難于做到的。

2、同行業(yè)之間只有競(jìng)爭(zhēng)關(guān)系，沒(méi)有合作關(guān)系。但現(xiàn)實(shí)中企業(yè)之間存在多種合作關(guān)系，不一定是你死我活的競(jìng)爭(zhēng)關(guān)系。

3、行業(yè)的規(guī)模是固定的，因此，只有通過(guò)奪取對(duì)手的份額來(lái)占有更大的資源和市場(chǎng)。但現(xiàn)實(shí)中企業(yè)之間往往不是通過(guò)吃掉對(duì)手而是與對(duì)手共同做大行業(yè)的蛋糕來(lái)獲取更大的資源和市場(chǎng)。同時(shí)，市場(chǎng)可以通過(guò)不斷的開(kāi)發(fā)和創(chuàng)新來(lái)增大容量。