Porter’s Five Forces

A strategic framework developed by Michael Porter for analyzing the structural drivers of industry profitability. The key insight: competition is broader than just direct rivals. Five forces together determine whether an industry can be profitable at all.

Industry attractiveness (how exciting or trendy it seems) has nothing to do with industry profitability. The forces determine that.

The Five Forces

Force	What It Measures
Rivalry Among Existing Competitors	How intensely firms compete on price, features, and market share
Threat of New Entrants	How easy it is for new competitors to enter the market
Threat of Substitutes	Whether customers can switch to a different product that meets the same need
Bargaining Power of Buyers	How much leverage customers have to demand lower prices or better terms
Bargaining Power of Suppliers	How much leverage input providers have to raise prices or restrict supply

Star Ratings: Industry Examples

• Five-Star Industry (all forces favourable): Soft drinks. Strong brand differentiation, low buyer power, high entry barriers → “a license to mint money.”
• Zero-Star Industry (all forces unfavourable): Airlines. Intense rivalry, powerful suppliers (Boeing, Airbus, labour unions), easy substitutes (cars, trains), and thin margins across the board.

Key Concepts

Dynamic analysis — the five forces are not a static snapshot. Industries evolve as buyer power shifts, technology changes, or substitutes emerge. Strategy must anticipate how forces are changing, not just measure them today.

Positive-sum vs. zero-sum rivalry — zero-sum battles (price wars, market share grabs) drag down profitability across the industry. Positive-sum strategies (differentiation, segmentation, expanding the profit pool) benefit everyone, including competitors.

Technology is not a sixth force — Porter was explicit: the internet was wrongly treated as a separate force. Technology is an enabling factor that shifts the balance of existing forces, not an independent one.

Strategy alignment — the framework only works if the entire organization understands the competitive positioning. Employees, partners, and channels must all align, not just the executive team.

How It Appears Per Course

ADMN 201

Introduced in Ch2 as a tool for assessing competitive situations within the external environment. Covered on the midterm; treated as context/background for further strategic analysis.

Cross-Course Connections

BusinessEnvironments — the five forces analyze the competitive slice of the external environment
DegreesOfCompetition — market structure (perfect → monopoly) describes who’s competing; five forces explains how profitable that competition is
ClassificationSystems-PortersFiveForces — industry boundary definition is a classification problem (PHIL252 connection)

Key Points for Exam/Study

• Five forces: rivalry, new entrants, substitutes, buyer power, supplier power
• Industry attractiveness ≠ industry profitability
• Airlines = zero-star. Soft drinks = five-star
• Technology is NOT a sixth force — it reshapes the existing five
• Dynamic: forces shift; strategy must anticipate that
• Positive-sum (differentiation) > zero-sum (price wars)

Open Questions

• How does a firm decide which force to respond to first when multiple forces are threatening simultaneously?

graph TD
    B[Threat of\nNew Entrants] -->|erodes margins| CENTER[Industry\nProfitability]
    C[Threat of\nSubstitutes] -->|limits pricing power| CENTER
    D[Bargaining Power\nof Buyers] -->|pressures margins down| CENTER
    E[Bargaining Power\nof Suppliers] -->|raises input costs| CENTER
    A[Rivalry Among\nExisting Competitors] -->|central competitive force| CENTER