Quick reference
Key formula / structure
Themes at the center, activities around them, a line wherever one activity helps another. Shade the one you want to change, and price its lines.
Memory aid
The lines that stop a rival copying you also stop you changing one box alone.
TL;DR
Write the two or three themes that make the position distinct. Around them, list the activities that carry them, including what the company deliberately does not do. Join two activities wherever one makes the other cheaper or better. Before any change to one activity, shade it, thicken its lines, and estimate what each line is worth. Decide with the gain from the change and the priced links side by side.
What Is Activity System Mapping?
An activity system map draws a company's strategy as a web. At the center sit a few themes, such as low cost or a particular kind of service. Around them sit the activities that carry those themes: how the company buys, makes, sells, staffs and serves. A line joins two activities wherever one makes the other cheaper or better. Michael E. Porter introduced the idea in "What Is Strategy?" in the Harvard Business Review in 1996. A dense web of lines is the sign of a strategy; a scatter of boxes with few lines is a list of good practices.
It is harder for a rival to match an array of interlocked activities than it is merely to imitate a particular sales-force approach, match a process technology, or replicate a set of product features.
— Michael E. Porter, "What Is Strategy?," Harvard Business Review (November–December 1996)
The map is usually drawn to show why a rival cannot copy you, and Porter made that case well: "Fit locks out imitators by creating a chain that is as strong as its strongest link." A competitor that copies a few boxes without the lines gets the cost of the change and none of the benefit. Continental Lite, his example, copied part of Southwest on some routes while staying a full-service airline elsewhere, and lost hundreds of millions of dollars. But the lines run both ways. Porter wrote that Southwest's 15-minute turnarounds depended partly on what it did not do: no meals, no seat assignment, no interline baggage transfers. Those absences were not gaps in the product. They held up other activities. So a map is also the list of what else moves when you change one box yourself. Southwest's September 2024 Investor Day materials said that ending free bags would cost more in lost demand than the fees would bring in, and it charged for bags from May 2025 anyway; in January 2026 it began assigning seats. Whatever the merits of each change, the map is the place where the question is asked before the decision: what does this activity hold up, and what is that worth?
Drawing an activity system map
From the themes to a priced decision, in five moves.
Name the themes
Two or three, at the center
List the activities
Including what you choose not to do
Draw the lines
Wherever one activity helps another
Shade the change
The activity under review
Price its lines
What each link is worth
Origin & context
Michael E. Porter set out the idea in "What Is Strategy?" in the November–December 1996 issue of the Harvard Business Review. He argued that operational effectiveness is not strategy, that a strategic position needs trade-offs, and that "strategy is creating fit among a company's activities." He described Southwest Airlines, IKEA and Vanguard as systems of activities that fit and reinforce one another, and concluded that positions built on such systems "are far more sustainable than those built on individual activities." The map is the drawing of that system.
Builds on: Michael E. Porter (1985), Competitive Advantage: Creating and Sustaining Superior Performance (the value chain and its activities); Michael E. Porter (1996), What Is Strategy?, Harvard Business Review; Michael E. Porter and Nicolaj Siggelkow (2008), Contextuality Within Activity Systems and Sustainability of Competitive Advantage, Academy of Management Perspectives.
Activity System Mapping in action
Southwest Airlines
The system rivals could not copy, changed by its owner
When Michael Porter wrote about Southwest in 1996, he described an airline built around what it did not do. It turned planes at the gate in 15 minutes, and part of the reason was that "with no meals, no seat assignment, and no interline baggage transfers, Southwest avoids having to perform activities that slow down other airlines." Continental had tried to copy part of it with Continental Lite and lost hundreds of millions of dollars.
On September 26, 2024, Southwest told investors it would move to assigned seats. Its reason was its customers: 80 percent of them, and 86 percent of passengers who chose other airlines, wanted seat assignments, and Southwest was flying farther than ever. The same release defended another piece of the system. Bags fly free, it said, was "the most important feature by far in setting Southwest apart," and, the company said, ending it "would drive down demand and far outweigh any revenue gains created by imposing and collecting bag fees." Its Investor Day slides, filed with the SEC, put the fees at $1 billion to $1.5 billion a year at most, against about $1.8 billion a year of lost share.
In October 2024 Southwest settled with the activist investor Elliott Investment Management, adding six new directors. In March 2025 it announced bag fees, and from May 28, 2025, it charged $35 for the first checked bag and $45 for the second, the first bag charges in its 54-year history. Whatever the merits of each change, the company had priced one of the links itself, on its own slides, before it cut it.
Assigned seats began on Southwest flights on January 27, 2026, ending open seating after more than half a century. One box on Porter's 1996 list, no seat assignments, was gone, and so were free bags, the feature Southwest had called its most important difference in its 2024 Investor Day release.
Continental Lite
Copying the boxes without the lines
Continental Airlines, Porter wrote, saw how well Southwest was doing and set out to match it on a number of point-to-point routes while staying a full-service airline everywhere else. Continental Lite cut meals and first-class service, raised departure frequency, lowered fares and shortened turnaround time at the gate.
But it kept the rest of Continental's system: travel agents, a mixed fleet, baggage checking and seat assignments. Its planes were delayed leaving congested hubs or slowed at the gate by baggage transfers, and late flights and cancellations generated a thousand complaints a day.
In Porter's words, "Trade-offs ultimately grounded Continental Lite. The airline lost hundreds of millions of dollars, and the CEO lost his job."
IKEA
The price tag at the center of the map
Porter described IKEA as a system tailored to young buyers who want style at low cost: self-service stores with every product shown in room-like settings, its own modular, ready-to-assemble furniture, a warehouse section where customers pick up their own boxes, and extras its rivals did not offer, such as in-store child care and extended hours.
IKEA puts the center of that map in one sentence of its own: "The first thing we design is the price tag." A flat-pack product, it says, "costs less because you assemble it yourself." The price is the theme; the design, the packing, the store and the customer's own car are the activities built to carry it.
In its 2024 financial year IKEA said it had substantially lowered prices across all 63 of its markets; total retail sales of its franchisees were EUR 45.1 billion, down 5.3%, or 4.0% adjusted for currency.
Vanguard
Every activity pointed at one theme
Porter used Vanguard as his example of the simplest kind of fit, every activity consistent with the strategy. It kept portfolio turnover low, distributed its funds directly rather than paying brokers, limited advertising, and tied its employees' bonuses to cost savings.
The deepest line on the map runs to ownership. Vanguard's funds own the management company, so there is no outside shareholder to pay a surplus to, and the surplus comes back largely as lower fees.
In February 2025 Vanguard cut fees on 168 share classes by an average of 20%, the largest cut in its history, and in February 2026 cut 84 more, bringing its all-fund average expense ratio to 0.06%.
Read the full story: why Vanguard's surplus comes back as fee cuts →
Using it in the room
Draw the map once, when the strategy is set or reviewed, and bring it out every time someone proposes changing one activity: a feature customers ask for, a cost cut, an outsourcing deal, a new fee. The meeting it is for is the one where a single change is about to be approved on its own merits.
Questions to ask
- ?What are the two or three themes that make our position different from our rivals'?
- ?What do we deliberately not do, and what does each absence hold up?
- ?Which activity would a rival have to give up its own business to copy?
- ?If we change this one activity, which lines does it cut, and what is each worth?
- ?Which activities have to change together if this one changes?
The 30-minute version
Five minutes: the two or three themes, at the center of a whiteboard. Ten minutes: the activities around them, including what you do not do. Ten minutes: the lines, drawn by the people who run the activities. Five minutes: shade the activity under review and name the two lines that matter most. The figures for those two lines are the homework before the decision.
Core Components
Central themes
The few ideas that run through many activities and make the position distinct. Porter called them "themes that pervade many activities, such as low cost, a particular notion of customer service, or a particular conception of the value delivered." Keep them to two or three.
Example
For IKEA, low prices with style for young buyers; for Vanguard, low cost for the investor.
Activities
The discrete things the company does, each specific enough to be done differently by a rival: not 'marketing' but 'limits advertising and relies on word of mouth'. Include what the company deliberately does not do, because an absence can carry as much weight as an activity.
Example
Southwest in Porter's 1996 account: 15-minute turnarounds, a standardized fleet of 737s, automated ticketing at the gate, no meals, no assigned seats.
Lines of fit
A line joins two activities when one makes the other cheaper or better. Porter named three kinds of fit: simple consistency with the strategy, activities that reinforce one another, and coordination that removes wasted effort.
Example
No seat assignment speeds boarding, which supports the 15-minute turnaround, which supports frequent departures with fewer aircraft.
Trade-offs
The choices the system rules out. Porter's test of a strategy is that more of one thing requires less of another; the map shows which boxes a rival would have to give up to copy you.
Example
An airline can serve meals, adding cost and slowing the gate, or it can not serve them, but it cannot do both without bearing major inefficiencies.
The price of a line
For the lines that matter most, a number: what the link is worth in cost, revenue or share. It is what turns the map from a picture into a decision tool.
Example
Southwest's 2024 slides put bag fees at $1 billion to $1.5 billion a year at most against about $1.8 billion a year of lost share.
Porter showed with simple arithmetic why systems are hard to copy: if a rival has a 90% chance of matching any one activity, its chance of matching two is .9 × .9 = .81, and of matching four, .9 × .9 × .9 × .9 = .66. The odds keep falling with every activity in the system.
When to Use Activity System Mapping
Before changing a product feature customers ask for
Problem it solves: The request looks like a simple addition, and nobody has traced what the missing feature was holding up.
Real-world application
An airline weighing assigned seats maps what open seating does for boarding, turnaround time and fares before it decides.
Answering a rival who copies you
Problem it solves: A competitor has matched a visible feature, and the board wants to know whether the position is at risk.
Real-world application
A retailer maps which of its activities the rival copied and which lines the rival cannot reach without giving up its own business.
Before outsourcing or cutting an activity
Problem it solves: The cost case looks at the activity alone, not at what other activities lose when it changes hands.
Real-world application
A fund manager tests whether moving distribution to brokers would raise costs elsewhere in a low-cost system.
Testing whether a strategy is a strategy
Problem it solves: The plan is a list of initiatives that could belong to any company in the industry.
Real-world application
A leadership team draws its map and finds most boxes have no lines to each other, which tells it the position is not yet distinct.
The things a company chooses not to do are easy to leave off the map and easy to add back to the product. Put them on the map as boxes with their own lines, or the first customer request to fill the gap will look free.
How to Apply Activity System Mapping: Step by Step
Before you start
- →A clear statement of the position: whom you serve and what you offer them that rivals do not
- →The people who run the main activities, not only the strategy team
- →Basic cost and revenue figures for the activities you expect to matter
Name the central themes
Write the two or three themes that make the position distinct, in plain words, at the center of the page.
Tips
- ✓Test each theme by asking whether a rival would describe itself the same way; if so, it is not distinct
Common mistakes
- ✗Writing values ('customer focus') instead of positions ('low fares on short routes')
List the activities, including the absences
List the specific activities that carry each theme, and the things the company deliberately does not do.
Tips
- ✓Phrase each activity so that a rival could do it differently
Common mistakes
- ✗Listing departments instead of activities
- ✗Leaving out the deliberate absences
Draw the lines
Join two activities wherever one makes the other cheaper or better, and each activity to the themes it carries.
Tips
- ✓Ask the owner of each activity what it depends on
Common mistakes
- ✗Drawing every activity to every other, which hides the lines that matter
Shade the activity under review
Mark the activity a decision would change: add, drop, outsource or reprice. Thicken its lines.
Tips
- ✓Do this for one change at a time
Common mistakes
- ✗Reviewing the change on its own page, away from the map
Price the lines
For each thick line, estimate what it is worth: the cost it saves, the revenue or share it holds, the time it buys.
Tips
- ✓A range is enough; the point is to compare the link with the gain from the change
Common mistakes
- ✗Pricing the change and not the links it cuts
Decide with the whole system in view
Make the decision with the gain from the change and the priced links side by side, and name what will be done about each link the change cuts.
Tips
- ✓Write down which links you expect to lose and how you will know
Common mistakes
- ✗Treating the map as a one-time exercise instead of the page every change is checked against
Showing the result
One slide: the map, with the themes at the center and the activity under review shaded. Its lines are drawn thick, each labeled with what it is worth. Beside it, two numbers: the gain from the change and the value of the links it cuts.
On the slide
- ✓The two or three themes
- ✓The activity under review and its lines, priced
- ✓The gain from the change, on the same slide
Left off
- ✕Every activity in the company (keep the ones that touch the decision)
- ✕Lines nobody can explain
- ✕Precision the estimates do not have
Value & Outcomes
Primary benefit
It shows why a position is hard to copy and, more usefully, what else moves when you change one part of it, before the change is made.
Additional benefits
- ✓Separates a real strategy from a list of good practices
- ✓Shows which of a rival's moves need an answer and which do not
- ✓Puts the deliberate absences on the page, where they can be defended
What you'll learn
- →How to draw the themes, activities and lines of fit
- →How to read a rival's copy against your whole system
- →How to price the links a change would cut
Typical outcomes
Best Practices
📋 Preparation
- •Write the position in one sentence before drawing anything
- •Invite the people who run the activities
- •Bring cost and revenue figures for the activities likely to matter
🚀 Execution
- •Keep the themes to two or three
- •Draw the absences as boxes
- •Thicken the lines of the activity under review
🔄 Follow-Up
- •Price the thick lines before the decision meeting
- •Keep the map as the page every proposed change is checked against
- •Redraw it when the position changes, not every planning cycle
💎 Pro Tips
- •If most boxes have no lines, the strategy is a list
- •Ask what a customer request would cost the rest of the system before saying yes to it
- •Map a rival too: the boxes it would have to give up to copy you are your protection
Ask the people who run each activity what it depends on and what depends on it. The lines executives draw from memory are usually the ones in the strategy deck, not the ones that carry the cost.
Limitations & Pitfalls
The lines are judgments. Two teams can draw different maps of the same business.
Mitigation: Draw the map with the people who run the activities, and put a number on the lines that drive the decision
It is a picture of today. It does not say whether the position is still the right one as customers change.
Mitigation: Use customer research and the economics of the market to test the themes; use the map to see what changing them costs
Fit can harden into rigidity. A system tuned for one position is hard to move when the market moves.
Mitigation: Mark the activities that would have to change together, and plan them as one move rather than one at a time
It shows links, not their size, unless you add the numbers yourself.
Mitigation: Price the thick lines before any decision that cuts them
What comes before and after
Run first
Lists the activities and what each costs; the map then shows how they fit.
Sets the position whose themes go at the center of the map.
Run next
Name the choices the map shows you must keep making, and defend them.
Record which links a change was expected to cut, so the next review can check what happened.
Where this comes fromMichael E. Porter introduced this (1996).
Sources & further reading
- Michael E. Porter (1996). What Is Strategy?. Harvard Business Review (November–December 1996).Strategy as fit among activities; Southwest, IKEA, Vanguard and Continental Lite; the three types of fit; the arithmetic of imitation.
- Southwest Airlines Co. (2024). 2024 Investor Day news release, Form 8-K exhibit. SEC EDGAR (September 26, 2024).Assigned seating and the customer research behind it; the bags fly free research; the Investor Day slides on bag fee revenue and share loss.
- CNBC (2024). Southwest and activist investor Elliott strike deal to keep CEO Bob Jordan, add six new directors. CNBC (October 24, 2024).
- Southwest Airlines (2025). Southwest Airlines Outlines Charges for Checked Baggage. Southwest Airlines Newsroom (March 11, 2025).$35 for the first checked bag and $45 for the second from May 28, 2025.
- Associated Press (2026). 50-year tradition of Southwest Airlines letting you choose your own seat comes to an end. Fortune (January 28, 2026).
- Inter IKEA Systems B.V. (2024). How we work: The IKEA value chain. IKEA Global.
- Inter IKEA Systems B.V. (2024). IKEA continues to lower prices for customers. IKEA Global newsroom (October 10, 2024).
- Vanguard (2026). Our history. Vanguard.
- Vanguard (2025). Announcing the largest fee cut in Vanguard history. Vanguard (February 3, 2025).
- Vanguard (2026). Vanguard To Deliver More Than Half a Billion in Expected Savings To Investors Since 2025. Vanguard (February 2, 2026).
More Management Frameworks
Other frameworks in the Stratrix library.
Scenario Planning
Scenario planning tests a strategy against three or four plausible futures instead of one forecast. It does not predict which future arrives. Its use is to find the bet a plan cannot afford to lose, while there is still time to hedge it.
Strategic AnalysisProfit Pools
A profit pool is the total profit an industry earns, mapped across every activity in its value chain. The money rarely sits where the revenue is. It gathers where customers stop shopping around, and the map exists to find that place first.
Strategic AnalysisSWOT Analysis
A strategic planning framework that evaluates an organization's internal Strengths and Weaknesses alongside external Opportunities and Threats to inform decision-making and strategy formulation.
Strategic AnalysisBCG Growth-Share Matrix
The BCG growth-share matrix plots a company's businesses by market growth and relative share, sorting them into stars, cash cows, question marks and dogs so leaders can decide where the portfolio's cash should go next.
Strategic Analysis7 Powers
7 Powers names the seven ways a business can earn more than its rivals for years, not quarters. Its test is strict: an advantage counts only when it pays and when something stops rivals from copying it. A great product that a rival can match is not a power.
Strategic AnalysisAnsoff Matrix
The Ansoff matrix sorts growth into four paths: market penetration, product development, market development and diversification. Each step away from today's products and customers adds risk, but the risk sits in what the company must learn, not in the box.
Tools to try
- Five Forces scorerFramework: Porter's Five Forces
- Ansoff move finderFramework: Ansoff Matrix
- SWOT builderFramework: SWOT Analysis
- Business model canvas builderFramework: Business Model Canvas
- Change readiness checkFramework: Kotter's 8-Step Change Model
- SMART goal builderFramework: SMART Goals
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