biz-porters-five-forces

asgard-ai-platform ｜ 商業與營運 ｜ 原文 ｜ MIT

用 Porter 五力評估產業的競爭結構與吸引力

---
name: "biz-porters-five-forces"
description: "套用 Porter 五力框架，評估產業的競爭動態與吸引力。當使用者需要分析產業的獲利結構、評估市場進入障礙、評估供應商或買方的議價能力、或了解競爭強度時使用，即使他們說的是「產業分析」或「這個市場值得進入嗎」，沒有明說 Porter 也一樣。"
metadata:
  category: "WP-13 商學院—策略"
  tags: ["business-strategy", "porters-five-forces", "industry-analysis"]
---

# Porter 五力分析

## 概述

Porter 五力透過檢視決定獲利能力的五種結構性力量，來評估產業層級的競爭動態。和 SWOT（公司層級）或 PESTEL（總體層級）不同，這個框架運作在**產業層級**，回答的是「這個產業有吸引力嗎？」，不是「這家公司強嗎？」

## 何時使用

**觸發條件：**
- 使用者問某個產業或市場是否有吸引力或有利潤
- 使用者在評估要不要進入新市場或新產業
- 使用者需要了解直接競爭對手以外的競爭動態
- 使用者提到「進入障礙」、「供應商議價能力」或「產業結構」

**何時不要用：**
- 針對特定公司的優勢／劣勢 → 用 SWOT
- 掃描總體環境 → 用 PESTEL
- 產品組合決策 → 用 BCG 矩陣

## 框架

```
鐵律：產業層級，不是公司層級

每一種力量描述的是「產業」結構，不是特定公司的地位。
「我們的供應商漲價了」是公司事件。
「這個產業的供應商集中，替代選擇很少」才是產業力量。

絕對不要分析單一公司的處境，要分析的是
產業內所有參與者都面對的結構性條件。
```

```
鐵律：每次都要分析全部五力

在下結論之前，要分析「全部」五力。跳過任何一力，
都會產生誤導的評估。競爭低但替代品威脅高的產業，
和競爭低且沒有替代品的產業，完全不同。
```

### 步驟 1：定義產業的邊界

分析各項力量之前，要先清楚定義：
- **什麼產業？** 要具體，是「台灣的外送平台」，不是「科技」
- **地理範圍**：全球、區域或國家
- **時間範圍**：目前狀態，或預測未來 3-5 年

邊界定錯，整個分析就失效。

### 步驟 2：分析每一力

把每一力對產業獲利能力的壓力，評為**高／中／低**：

**1. 新進入者的威脅**：新玩家進入有多容易？
- 資本需求、規模經濟、品牌忠誠度、法規障礙
- 取得配銷通路、轉換成本、既有業者的反應

**2. 供應商的議價能力**：供應商能主導條件嗎？
- 供應商集中度、投入要素的獨特性、轉換成本
- 往下游整合的威脅、採購量對供應商的重要性

**3. 買方的議價能力**：顧客能主導條件嗎？
- 買方集中度、價格敏感度、產品差異化
- 往上游整合的威脅、轉換成本、資訊的可得性

**4. 替代品的威脅**：其他產品能滿足相同的需求嗎？
- 替代品的性價比、轉換成本
- 買方轉向替代品的傾向、功能上的等價性

**5. 產業內的競爭**：現有玩家之間的競爭有多激烈？
- 競爭者的數量與規模、產業成長率
- 產品差異化、退出障礙、固定成本結構

### 步驟 3：評估整體的產業吸引力

把五力綜合成整體評估：
- 越多力量 = 高壓力 → 越沒吸引力（獲利能力較低）
- 越多力量 = 低壓力 → 越有吸引力（獲利能力較高）
- 找出**主導力量**，也就是最限制獲利能力的那一個

### 步驟 4：策略意涵

根據分析：
- 公司能影響或重塑哪些力量？
- 公司該如何定位，才能把負面力量降到最低？
- 未來有哪些結構性改變，可能讓各力量的消長改變？

## 輸出格式

```markdown
# Porter 五力：{地區}的{產業}

## 產業定義
- 產業：...
- 地理範圍：...
- 時間範圍：...

## 五力評估

| 力量 | 壓力 | 關鍵驅動因素 |
|-------|----------|-------------|
| 新進入者的威脅 | 高/中/低 | {前 2-3 個驅動因素} |
| 供應商議價能力 | 高/中/低 | {前 2-3 個驅動因素} |
| 買方議價能力 | 高/中/低 | {前 2-3 個驅動因素} |
| 替代品的威脅 | 高/中/低 | {前 2-3 個驅動因素} |
| 產業內的競爭 | 高/中/低 | {前 2-3 個驅動因素} |

### 1. 新進入者的威脅：{評級}
{附上證據的分析}

### 2. 供應商的議價能力：{評級}
{附上證據的分析}

### 3. 買方的議價能力：{評級}
{附上證據的分析}

### 4. 替代品的威脅：{評級}
{附上證據的分析}

### 5. 產業內的競爭：{評級}
{附上證據的分析}

## 整體評估
- 產業吸引力：高 / 中 / 低
- 主導力量：{哪一力最限制獲利能力}
- 獲利能力展望：...

## 策略意涵
1. ...
2. ...
```

## 範例

### 正確的應用

**情境：** 台灣手搖飲料產業的五力分析

| 力量 | 壓力 | 推理 |
|-------|----------|-----------|
| 新進入者 | **高** | 資本需求低（開一間店約 NT$500K）、法規障礙極小、有很多加盟選項 |
| 供應商議價能力 | **低** | 茶葉和粉圓是大宗投入，供應商很多；沒有單一供應商有定價能力 |
| 買方議價能力 | **高** | 消費者的轉換成本為零、步行範圍內有數百個選擇、價格敏感度高 |
| 替代品 | **中** | 咖啡、便利商店飲料和自己泡的茶，都能滿足類似的「下午茶飲」需求，但珍珠奶茶有很強的文化偏好 |
| 競爭 | **高** | 市場飽和，有數千間店，中階品牌之間差異化低，經常打價格戰 |

**整體**：吸引力低，高進入威脅 + 高競爭 + 高買方議價能力，壓縮了利潤。

### 錯誤的應用

**情境：** 同一個手搖飲料產業

**哪裡出錯：**
- 「我們的旗艦店人流很旺」→ 這是**公司**的事實，不是**產業**的力量。違反鐵律：分析產業結構，不是個別公司的地位。
- 只分析了「競爭」和「新進入者」，跳過另外三力 → 違反鐵律：必須有全部五力。缺少供應商／買方／替代品的分析，會得到不完整的圖像。

## 常見陷阱

- **把公司的地位和產業結構搞混**：「我們有強大的品牌」和五力無關。「品牌忠誠度為整個產業創造了很高的進入障礙」才相關。
- **忽略替代品**：大多數分析師會低估這一力。要問：「如果這個產業的價格漲了一倍，顧客會轉向什麼？」
- **靜態分析**：五力描述的是目前的結構。產業會演變，要註明正在出現的轉變（例如數位顛覆降低了進入障礙）。
- **產業邊界太廣**：「食品產業」沒辦法分析。要縮小到擁有共同競爭動態的特定區隔。
- **把各力視為彼此獨立**：各力之間會交互作用。高買方議價能力 + 低轉換成本，會放大新進入者的效應。

## 參考資料

- 與 SWOT、PESTEL 和其他策略框架的比較，見 `references/framework-comparison.md`

---
name: "biz-porters-five-forces"
description: "Apply Porter's Five Forces framework to assess industry competitive dynamics and attractiveness. Use this skill when the user needs to analyze an industry's profitability structure, evaluate market entry barriers, assess supplier or buyer bargaining power, or understand competitive intensity — even if they say 'industry analysis' or 'is this market worth entering' without naming Porter's explicitly."
metadata:
  category: "WP-13 商學院—策略"
  tags: ["business-strategy", "porters-five-forces", "industry-analysis"]
---

# Porter's Five Forces Analysis

## Overview

Porter's Five Forces assesses industry-level competitive dynamics by examining five structural forces that determine profitability. Unlike SWOT (company-level) or PESTEL (macro-level), this framework operates at the **industry level** — it answers "is this industry attractive?" not "is this company strong?"

## When to Use

**Trigger conditions:**
- User asks whether an industry or market is attractive or profitable
- User evaluates whether to enter a new market or industry
- User needs to understand competitive dynamics beyond direct competitors
- User mentions "barriers to entry", "supplier power", or "industry structure"

**When NOT to use:**
- For company-specific strengths/weaknesses → use SWOT
- For macro-environment scanning → use PESTEL
- For product portfolio decisions → use BCG Matrix

## Framework

```
IRON LAW: Industry-Level, Not Company-Level

Each force describes the INDUSTRY structure, not a specific company's position.
"Our supplier raised prices" is a company event.
"Suppliers in this industry are concentrated with few alternatives" is an industry force.

NEVER analyze a single company's situation — analyze the structural conditions
all players in the industry face.
```

```
IRON LAW: All Five Forces, Every Time

Analyze ALL five forces before drawing conclusions. Skipping forces produces
misleading assessments. An industry with low rivalry but high substitute threat
is very different from one with low rivalry and no substitutes.
```

### Step 1: Define the Industry Boundary

Before analyzing forces, clearly define:
- **What industry?** Be specific — "food delivery platforms in Taiwan" not "tech"
- **Geographic scope**: global, regional, or national
- **Time horizon**: current state or projected 3-5 years

Getting the boundary wrong invalidates the entire analysis.

### Step 2: Analyze Each Force

Rate each force as **High / Medium / Low** pressure on industry profitability:

**1. Threat of New Entrants** — How easy is it for new players to enter?
- Capital requirements, economies of scale, brand loyalty, regulatory barriers
- Access to distribution channels, switching costs, incumbents' response

**2. Bargaining Power of Suppliers** — Can suppliers dictate terms?
- Supplier concentration, uniqueness of inputs, switching costs
- Forward integration threat, importance of volume to supplier

**3. Bargaining Power of Buyers** — Can customers dictate terms?
- Buyer concentration, price sensitivity, product differentiation
- Backward integration threat, switching costs, information availability

**4. Threat of Substitutes** — Can other products fulfill the same need?
- Price-performance of substitutes, switching costs
- Buyer propensity to substitute, functional equivalence

**5. Industry Rivalry** — How intense is competition among existing players?
- Number and size of competitors, industry growth rate
- Product differentiation, exit barriers, fixed costs structure

### Step 3: Assess Overall Industry Attractiveness

Synthesize the five forces into an overall assessment:
- More forces = High pressure → less attractive (lower profitability)
- More forces = Low pressure → more attractive (higher profitability)
- Identify the **dominant force** — the one that most constrains profitability

### Step 4: Strategic Implications

Based on the analysis:
- Which forces can the company influence or reshape?
- Where should the company position to minimize negative forces?
- What structural changes might shift forces in the future?

## Output Format

```markdown
# Porter's Five Forces: {Industry} in {Geography}

## Industry Definition
- Industry: ...
- Geographic scope: ...
- Time horizon: ...

## Five Forces Assessment

| Force | Pressure | Key Drivers |
|-------|----------|-------------|
| Threat of New Entrants | High/Med/Low | {top 2-3 drivers} |
| Supplier Power | High/Med/Low | {top 2-3 drivers} |
| Buyer Power | High/Med/Low | {top 2-3 drivers} |
| Threat of Substitutes | High/Med/Low | {top 2-3 drivers} |
| Industry Rivalry | High/Med/Low | {top 2-3 drivers} |

### 1. Threat of New Entrants: {rating}
{Analysis with evidence}

### 2. Bargaining Power of Suppliers: {rating}
{Analysis with evidence}

### 3. Bargaining Power of Buyers: {rating}
{Analysis with evidence}

### 4. Threat of Substitutes: {rating}
{Analysis with evidence}

### 5. Industry Rivalry: {rating}
{Analysis with evidence}

## Overall Assessment
- Industry attractiveness: High / Medium / Low
- Dominant force: {which force most constrains profitability}
- Profitability outlook: ...

## Strategic Implications
1. ...
2. ...
```

## Examples

### Correct Application

**Scenario:** Five Forces for the Taiwan bubble tea industry

| Force | Pressure | Reasoning |
|-------|----------|-----------|
| New Entrants | **High** | Low capital requirements (~NT$500K to open a shop), minimal regulatory barriers, many franchise options available |
| Supplier Power | **Low** | Tea leaves and tapioca are commodity inputs with many suppliers; no single supplier has pricing power |
| Buyer Power | **High** | Zero switching costs for consumers, hundreds of options within walking distance, high price sensitivity |
| Substitutes | **Medium** | Coffee, convenience store drinks, and home-brewed tea serve similar "afternoon drink" need, but bubble tea has strong cultural preference |
| Rivalry | **High** | Saturated market with thousands of shops, low differentiation among mid-tier brands, frequent price wars |

**Overall**: Low attractiveness — high entry threat + high rivalry + high buyer power squeeze margins.

### Incorrect Application

**Scenario:** Same bubble tea industry

**What went wrong:**
- "Our flagship store has strong foot traffic" → This is a **company** fact, not an **industry** force. Violates Iron Law: analyze industry structure, not individual company position.
- Only analyzed "Rivalry" and "New Entrants", skipped other three forces → Violates Iron Law: all five forces required. Missing supplier/buyer/substitute analysis gives incomplete picture.

## Gotchas

- **Confusing company position with industry structure**: "We have a strong brand" is not relevant to Five Forces. "Brand loyalty creates high barriers to entry for the industry" is.
- **Overlooking substitutes**: Most analysts underweight this force. Ask: "If prices in this industry doubled, what would customers switch to?"
- **Static analysis**: Five Forces describes current structure. Industries evolve — note emerging shifts (e.g., digital disruption lowering entry barriers).
- **Industry boundary too broad**: "The food industry" is not analyzable. Narrow to a specific segment with shared competitive dynamics.
- **Treating forces as independent**: Forces interact. High buyer power + low switching costs amplifies the effect of new entrants.

## References

- For comparison with SWOT, PESTEL, and other strategy frameworks, see `references/framework-comparison.md`