Porter's Five Forces

波特五力分析 · Source: Michael Porter

Assessing the long-term attractiveness of an industry or market — both before entry and to clarify your position once inside

Core Concept

Porter's 1979 HBR classic: an industry's profitability is determined by the balance of five forces — threat of new entrants, threat of substitutes, supplier bargaining power, buyer bargaining power, intensity of rivalry. The analysis tells you "how much is structural vs how much is company-specific" — good strategy is choosing the right battlefield before fighting.

✓ When to use this

When evaluating whether to enter a new market, assessing long-term profit potential of an existing one, or explaining why an industry is broadly low- (or high-) margin. Also useful in early-stage founding to judge battlefield structure.

✗ When not to use this

Skip in fast-moving, tech-disrupted markets — Porter assumes relatively stable industry structures. Also unsuitable for analyzing a single company's performance, which is internal not structural.

Questions you will be asked

Using this framework, you will work through —

1.What industry or market are you analyzing? Define scope and boundaries first.
2.How high is the threat of new entrants? What are the barriers (capital, tech, brand, scale, regulation)?
3.Threat of substitutes? What non-direct alternatives might your customers turn to?
…and 3 more

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Worked example

Expand to see what a filled-in run looks like

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Situation

考慮是否進入「中小企業 SaaS HR 系統」市場——朋友邀我合作，他覺得有機會。我先做五力分析判斷產業結構。

1. What industry or market are you analyzing? Define scope and boundaries first.

中小企業（30–500 人）SaaS HR 系統，台灣市場。

2. How high is the threat of new entrants? What are the barriers (capital, tech, brand, scale, regulation)?

新進入者威脅：高。技術門檻不高、雲端架構成熟、同業已 10+ 家。資金門檻中等。品牌建立慢但不貴。

3. Threat of substitutes? What non-direct alternatives might your customers turn to?

替代品：Excel + Google Form（很多 30 人以下還在用）、人事外包公司、企業內部 ERP 加裝模組。轉換成本不高。

4. Supplier vs buyer bargaining power? Which end squeezes your margin?

供應商議價力：低（雲端服務 commodity）。買家議價力：高——客戶集中度低但 churn 容易、選擇多。

5. Intensity of rivalry? Number of competitors, growth rate, differentiation, exit barriers?

現有競爭強度：高。10+ 家業者中沒人佔超過 20% 市佔；產業成長 5–8%（中等）；產品差異化低（功能 80% 重疊）；造成價格戰。

6. Overall assessment: how attractive is this industry? Should you enter, exit, or reposition?

結論：產業吸引力低——五力中三力強烈不利。除非能找到強差異化縫隙（如特定產業 vertical SaaS、AI 自動化某具體流程），否則不該進入。回去問朋友他的差異化主張是什麼。

Use it inside ChatGPT / Claude

Paste the prompt below and the AI will walk you through this framework, one question at a time.

你現在是引導使用者做 Porter Five Forces 分析的教練。
依序問：
1) 你正在分析的產業/市場是什麼？範圍要具體。
2) 新進入者威脅：進入門檻是什麼（資金、技術、品牌、規模、法規）？高/中/低？
3) 替代品威脅：客戶可能轉用什麼非直接競品？（記得想非顯而易見的替代）
4) 供應商議價力 vs 買家議價力：哪一端在擠你的利潤？
5) 現有競爭強度：同業數量、成長率、差異化、退出門檻？
6) 綜合五力，這個產業吸引力如何？該進入、退出、還是改變定位？

特別提醒：產業吸引力低的市場可以贏，但需要結構性差異化。差異化不夠 = 用力打仗也輸給結構。

互動規則：
1. 一次只問一題，等使用者回答後再進入下一題。
2. 使用者答完所有題目前，不要做總結或下結論。
3. 若答案太抽象、太籠統，請追問一次具體例子或數字後再繼續。
4. 全部答完後，輸出三段：(a) 摘要使用者的關鍵判斷；(b) 你看到的盲點或張力；(c) 一個具體下一步行動建議。
5. 不要替使用者做決定，只把判斷攤開讓他自己決定。

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2026-05-03 · 4 min

波特五力：先選戰場，再打仗

一個產業會不會賺錢，多半在你進去之前就決定了。

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