fatihguner/foreman/porters-five-forces

Read runtime and advisory rules before applying this skill. Other Foreman layers and the catalog are in ../../content/, relative to this SKILL.md.

Porter's Five Forces

Most people use Porter's Five Forces wrong. They fill in the five boxes, label each force as "high," "medium," or "low," and conclude that they have performed strategic analysis. They have not. Michael Porter's framework, introduced in his 1979 Harvard Business Review article "How Competitive Forces Shape Strategy" and elaborated in Competitive Strategy (1980), is not a checklist. It is a theory of profitability -- an explanation of why some industries are structurally profitable and others are not, and why positioning within an industry matters more than operational excellence. The five forces determine the profit potential of an industry. Understanding them determines whether a startup is entering a gold mine or a tar pit. Misunderstanding them -- which is the norm -- produces strategies that fight industry structure rather than leveraging it.

The Framework

The Five Forces

Porter's model identifies five competitive forces that collectively determine the intensity of competition and, therefore, the profit potential of any industry.

                    ┌───────────────────────┐
                    │   THREAT OF NEW       │
                    │   ENTRANTS            │
                    └───────────┬───────────┘
                                │
                                ▼
┌──────────────┐    ┌───────────────────────┐    ┌──────────────┐
│ BARGAINING   │───▶│   INDUSTRY RIVALRY    │◀───│ BARGAINING   │
│ POWER OF     │    │   (among existing     │    │ POWER OF     │
│ SUPPLIERS    │    │    competitors)        │    │ BUYERS       │
└──────────────┘    └───────────┬───────────┘    └──────────────┘
                                │
                                ▼
                    ┌───────────────────────┐
                    │   THREAT OF           │
                    │   SUBSTITUTES         │
                    └───────────────────────┘

Force 1: Threat of New Entrants

New entrants bring new capacity, new resources, and the desire to gain market share. The seriousness of the threat depends on barriers to entry:

For startups: you are the new entrant. The barriers you overcome to enter are the same barriers that will protect you once inside -- if you build them.

Force 2: Bargaining Power of Suppliers

Suppliers are powerful when they are concentrated, provide differentiated inputs, face low switching costs for their own business, or can credibly threaten forward integration. Powerful suppliers capture value by charging higher prices or reducing quality.

For startups: key suppliers include cloud providers, payment processors, talent pools, and API providers. A startup dependent on a single API provider whose pricing can change unilaterally faces significant supplier power. Diversification, commoditization of inputs, and building proprietary alternatives are defensive strategies.

Force 3: Bargaining Power of Buyers

Buyers are powerful when they are concentrated (few large customers), purchase large volumes, face low switching costs, or can credibly threaten backward integration (building the product themselves). Powerful buyers capture value by demanding lower prices or higher quality.

For startups: customer concentration is the most common buyer power trap. A startup where one customer represents 40% of revenue has granted that customer enormous leverage. The strategic response is to diversify the customer base as early as possible and to create switching costs through integration depth, data lock-in, or workflow embedding.

Force 4: Threat of Substitutes

A substitute is not a direct competitor -- it is a different product that serves the same need. The threat is highest when the substitute offers an attractive price-performance trade-off and when switching costs are low.

For startups: the most dangerous substitute is often "doing nothing" or "doing it manually." A project management tool competes not just with other tools but with spreadsheets, email chains, and whiteboards. Understanding the true substitutes -- especially non-consumption -- prevents strategic myopia.

Force 5: Industry Rivalry

Rivalry is intense when competitors are numerous and roughly equal in size, industry growth is slow, fixed costs are high, products are undifferentiated, and exit barriers prevent competitors from leaving. Intense rivalry drives down prices and profitability for all participants.

For startups: entering a market with intense rivalry among well-funded incumbents is the most common cause of startup failure-by-competition. The five forces analysis should prevent this by revealing unattractive industry structures before capital is committed.

The Synthesis: Industry Attractiveness

The five forces collectively produce an industry attractiveness assessment:

• Attractive industry: High barriers to entry, weak supplier and buyer power, few substitutes, moderate rivalry. Incumbents earn above-average returns.
• Unattractive industry: Low barriers, powerful suppliers and buyers, many substitutes, intense rivalry. Even good companies earn below-average returns.

Porter's deepest insight: company strategy should begin with industry selection. Competing brilliantly in a structurally unattractive industry produces mediocre returns. Competing adequately in a structurally attractive industry produces superior returns. Industry structure trumps execution.

Prompts

Prompt 1 -- Full Five Forces Analysis:

Conduct a Porter's Five Forces analysis of my industry. I compete in [describe industry/market segment]. For each force, assess the intensity (Weak/Moderate/Strong) and identify the specific factors driving that assessment. Then provide an overall industry attractiveness rating and its implications for my startup's strategy. Present the analysis as both a summary table and a detailed narrative for each force.

Prompt 2 -- Entry Barrier Assessment:

I am considering entering [describe market/industry]. Using Porter's framework, assess the barriers to entry I will face. For each barrier type (economies of scale, capital requirements, switching costs, distribution access, regulatory requirements, network effects, brand loyalty), rate the height of the barrier and my realistic ability to overcome it. Then assess: once I overcome these barriers, which ones will protect me from subsequent entrants? Identify the barriers I should actively build.

Prompt 3 -- Competitive Position Optimization:

Given this Five Forces analysis of my industry [paste or describe analysis], help me design a competitive position that exploits the structure rather than fighting it. Where are the pockets of profitability? Which customer segments face the least buyer power? Which supplier relationships can be restructured? What positioning would reduce our exposure to rivalry? Frame the output as a strategic positioning recommendation.

Prompt 4 -- Dynamic Forces Projection:

My industry's five forces are currently [describe current state]. Project how each force is likely to change over the next 3-5 years, considering these trends: [describe relevant technology, regulatory, demographic, or competitive trends]. Which forces are strengthening? Which are weakening? How should my strategy adapt to the evolving industry structure? Present as a current vs. future comparison for each force.

Prompt 5 -- Substitute Threat Deep Dive:

Analyze the substitute threats to my product/service. My offering is [describe]. Go beyond direct competitors and identify ALL substitutes -- including non-consumption, manual alternatives, and products from adjacent industries that serve the same underlying need. For each substitute, assess: price-performance relative to my offering, switching costs from the substitute, and the conditions under which customers would prefer the substitute. Rank substitutes by threat level.

Use Cases

Idea-Stage Founder Evaluating Two Market Opportunities A technical founder with expertise in computer vision must choose between building a quality inspection product for manufacturing (Market A) and a visual search product for e-commerce (Market B). The Five Forces analysis reveals that Market A has moderate barriers to entry (domain expertise required), weak buyer power (fragmented customer base of thousands of factories), few substitutes (manual inspection is costly and error-prone), and moderate rivalry (three incumbents, none dominant). Market B has low barriers (many CV APIs available), strong buyer power (a few large e-commerce platforms dominate demand), strong substitutes (text search is free and familiar), and intense rivalry (dozens of startups, several well-funded). The structural analysis clearly favors Market A, independent of the founder's personal preference.

Growth-Stage SaaS Company Experiencing Margin Pressure A $10M ARR vertical SaaS company faces declining margins despite growing revenue. The Five Forces analysis reveals the cause: buyer power has increased as three enterprise customers now represent 55% of revenue, and each is demanding volume discounts and custom features. Supplier power has also increased as the company's reliance on a single cloud provider and a single data vendor has deepened. The strategic response targets both forces: a customer diversification initiative to reduce concentration below 20% per customer, and a multi-cloud architecture initiative to restore supplier optionality.

Scale-Stage Company Evaluating Vertical Integration A 1,000-person company evaluates whether to build an in-house capability currently provided by a supplier. The Five Forces lens reframes this decision: the supplier has strong bargaining power (proprietary technology, few alternatives, high switching costs). Vertical integration would eliminate this force entirely. The analysis also reveals that the in-house capability could become a new revenue line -- the company could become a supplier to its own competitors, converting a cost center into a profit center while simultaneously neutralizing a competitive force.

Anti-Patterns

1. Using Five Forces as a static snapshot. Industry structure evolves. Technology shifts, regulatory changes, and new entrants alter the balance of forces continuously. An analysis conducted once and never updated becomes a historical artifact rather than a strategic tool. The framework must be reapplied at least annually, and whenever a significant structural change occurs.

1. Confusing competitors with substitutes. Direct competitors offer similar products. Substitutes serve the same need through different means. Mistaking one for the other leads to strategic myopia -- fighting feature wars with competitors while a substitute captures the market from an entirely different direction.