Porter's Five Forces

The first numbers on the table when a new business gets reviewed are almost always market size and growth rate. "This market is growing 30 percent a year" was enough to get an approval. Then a few years pass and it turns out every company that entered is losing money. Plenty of markets look like that: users keep arriving and not one of the operators keeps a profit.

The question missing from those reviews was who ends up holding the money the market creates. Customers can spend more every year, but if that spending leaks out to suppliers or distribution channels, the company that built the product keeps none of it. The review document had a line for market growth and no line for where the money goes. So meetings ended somewhere between "it's big, let's go in" and "this feels wrong."

Five Forces splits that question into five places to check. It fixes in advance the five directions money can leak toward, then rates how strong each one is right now. What the framework changed is that a market's attractiveness gets answered by structure instead of by a growth rate.

Draw the boundary of the industry first, rate each of the five forces as strong, moderate or weak, then attach a response to the strongest one.

1. Set the industry boundary. Make it as broad as "the software industry" and no force can be rated at all. Narrowing to something like "team document collaboration tools in Korea" is what makes the suppliers and buyers identifiable.
2. Work through the five forces. Each one asks a specific question.
   • Threat of new entrants — how easy is it to come in? Strong if a few engineers can ship something comparable, weak if the business needs a factory or a license.
   • Threat of substitutes — is there another way to solve the same problem? The substitute for a collaboration document tool isn't a rival product; it's the habit of dropping files into a chat thread.
   • Supplier power — is there anyone whose price you can't push down? If your cloud provider raises prices 20 percent and you can't move, that side holds the power.
   • Buyer power — can customers force your price down? When three accounts make up 60 percent of revenue, refusing what those three ask for is hard.
   • Rivalry among existing competitors — how hard are the incumbents fighting? Small product differences plus low switching costs push everyone toward discounting.
3. Write a rating and one line of evidence for each force. Something like "buyers strong — top 3 accounts are 60 percent of revenue" attaches a number, which is what lets the next person re-examine the judgment.
4. Pick the single strongest force. Don't average the five. The profit gets taken by whichever force is strongest, and a weak rating elsewhere doesn't offset it.
5. Look for a way to weaken that force. Strong entry threat calls for building a moat; strong buyer power calls for widening the customer base so no single account carries that much weight. If all five come back strong, the answer may be a different industry rather than a response.

The places it fits are deciding whether to enter a new industry, reworking a business model, and judging whether to invest in someone else's company. In all three the structure of the board matters more than any individual competitor. Running the framework once also narrows down where a competitive advantage has to be built, because the strongest force is exactly where the advantage needs to sit.

There are four limits. The first is that the conclusion flips depending on where you draw the boundary. Narrowed to document collaboration tools, entry threat comes out strong; widened to collaboration software as a whole, it drops to moderate. So write the boundary down first and record why you drew it there. The second is that the output is a snapshot. Whether a rating from six months ago still holds has to be rechecked, and in fast-moving technical areas the shelf life is shorter than that. The third is that forces outside the five boxes go missing. Regulation, complements that make your product more valuable when used together, and effects where the product improves as more people use it have no seat in this framework. The fourth is that strong-versus-weak calls carry a lot of judgment, which is the reason step 3 asks for a number.

"Buyer power is by far the strongest of the five. Three accounts are 60 percent of revenue."

The diagnosis is that customer concentration, not the industry structure itself, is cutting into profit.

"Entry barriers are low here, so a single feature won't hold. We need to make leaving harder."

Entry threat came back strong, so the response has to come from somewhere other than product features.

"Growth looks fine but the structure is bad. Three of the five came back strong."

A market getting bigger and a company keeping profit inside it are separate questions.

Grace ran this framework when Pagedeck looked at spinning contract management out as a separate business. Theo said a comparable product could be built in three months, so entry threat was rated strong. Sofia said most customers were already served well enough by the e-signature service they had, so substitute threat came back strong too. Suppliers and buyers were moderate, and rivalry among incumbents was strong.

With three of the five strong, the decision was to attach it as a feature of the existing product rather than spin it out. The years of documents already sitting in Pagedeck were a condition no new company could copy, and that was the only defense left on the table.

The most common misreading is that strong forces mean the company is doomed. Ratings arrive as strong and weak, so the output naturally looks like a report card. But what the framework answers is the average profitability of the whole industry, not the performance of one company. Even in a badly structured industry, a single company that has piled up assets nobody can easily move away from often keeps a profit. Read the ratings as a company's grade and you either give up an opportunity because the structure looks bad, or walk in unprepared because it looks good.

Nearly as common is treating it as competitor analysis, which the word competition in the name invites. But rivalry between competitors is one of five, and the other four look at parties who are not competitors. Leave that misreading in place and you get a document with only the rivalry box filled in, ending at "competition is intense" — something everyone already knew.