Scenario Planning

Where it came from

Herman Kahn at the RAND Corporation in the 1950s, thinking through nuclear futures nobody wanted to imagine, gave the method its name and its reputation for saying the unsayable. Pierre Wack, running a small planning team at Shell in the early 1970s, gave it its purpose. Wack’s team built scenarios in which the oil-producing countries organised, cut supply and pushed the price up several times over. When the embargo came in October 1973 and did exactly that, Shell’s managers had already thought it through, and the company came out of the decade stronger than any rival.

Wack was clear that the point was not to predict. It was to change what the managers could imagine, so that when the world moved they recognised it. He wrote two articles for Harvard Business Review in 1985 that are still the best account. Peter Schwartz, who succeeded him at Shell, turned the method into a book, The Art of the Long View, in 1991.

The two-axes grid, four worlds from the two most decisive uncertainties, is the version Schwartz taught and the version Greggle uses.

Why it works

Forecasting picks one future and bets on it. Scenarios pick the two most uncertain and most decisive forces, cross them, and give you four futures to rehearse. You stop asking "what will happen" and start asking "what would I do if", which is a question you can actually answer now.

Two things make it work rather than just interesting. The axes have to be independent: if knowing how one lands tells you how the other does, the four worlds are really two, and the grid is decoration. And the signposts have to be planted: early, observable signs that one world is arriving rather than another. A scenario nobody can check against reality is a story.

When to reach for it, and when not to

Reach for it when the right answer depends on things outside your control that could genuinely go either way within the time you care about. A Challenge whose outcome depends on how the world turns, an Opportunity whose value does, a Decision with a long horizon.

It is the wrong tool for a decision whose uncertainties are all inside your control; that is Options and Criteria or Force Field Analysis. And it is wasted on a horizon so short that nothing can diverge, or so long that the decision no longer exists. Greggle suggests it on a Challenge and an Opportunity.

How to run it

With a pen, on one sheet of paper.

Name the decision the scenarios are for, the horizon, and what is effectively settled between now and then. The settled things hold in every world; they are the walls of the grid, not its axes.
List the uncertainties: things that could genuinely land either way, with both ends named. Weigh each against the others: decisive, shapes the decision, or background.
Promote exactly two to axes: the most decisive pair that are independent of each other. Ask the question out loud: would knowing how one lands tell you how the other does? If yes, keep the more decisive and find another.
Cross the axes. Each corner is a world. Name each one, say which end of each axis it takes, and write the plausible route from today to it. All four get equal effort, including the one you find implausible.
For each world, list what it makes true that isn’t true today, and what you would do about it: now, or prepared now and done then.
Plant signposts: early, observable signs that a world is arriving, each tied to a world by name and to a place you actually look. Then write the moves that are right in every world, the bets that back one world, and the date you will read the signposts next.

There is a one-page card with these steps and a blank grid to fill in, made to print on A4. Or the PDF.

On a Greggle board

Pick Scenario Planning on a Challenge or Opportunity board and Greggle proposes five steps: the decision and horizon, the uncertainties with three to start, four worlds each with two implications to start, the signposts, and what you would do now.

The Saturday job, inside the four worlds: Full Saturdays, Free and easy, Pitch and pen and Desk-bound, the first with its route from today — a real board · the Saturday job, the four worlds · click a step to open it

Inside 2 — The uncertainties: the board one level down — a real board · the Saturday job, the four worlds · click a step to open it

1The decision and the horizonWhat will be done differently. How far out. What is effectively settled and holds in every world.

2The uncertaintiesThree to eight. Each: both ways it could land; decisive, shapes or background; an axis or not; and whether the other axis would predict it.

3The four worldsEach corner: a name people will use, which end of each axis, how it comes about from today. Then implications, each with what you would do.

4The signpostsThree to twelve. Each: the sign, which world it points to, where you would see it.

5What you would do nowThe moves right in every world. The bets, and which world each backs. When the signposts get read next.

not on the boardThe storyWack’s scenarios were narratives. The route-from-today field is where that lives here.

Nothing is added until you have looked at it. Open any step and it becomes a board of its own. Steps that cannot sensibly be cut smaller get marked as actions, and every action collects in one flat list.

What the check looks for

One button reads the whole branch back. On this method it reports, among other things:

Three or more uncertainties are each named as an axis. A grid has two.
An axis has never been checked for independence from the other, or admits it is correlated and nothing replaces it.
Worlds have been named and not one has a plausible route from today.
Nothing has been written under the signposts, which is what separates scenario planning from science fiction.

A worked example

a Decision · whether to take the Saturday job at the garden centre for the year

The decision and horizonWhether to say yes to eight hours every Saturday from October to next July. Settled: exams are in May whatever happens, the pay is fixed, and the garden centre wants an answer by the end of September.

UncertaintiesWhether I make the first team, which plays Saturday mornings. Decisive. Whether this year’s coursework load is as heavy as everyone says. Decisive. Whether the band gets gigs. Shapes it. Whether the garden centre stays open through winter. Background. Axes: first team and coursework. Would one predict the other? No, they can land in any combination.

The four worldsFull Saturdays: first team, heavy coursework. The job is impossible; I’d be quitting by November. Free and easy: no team, light coursework. The job is the best thing on offer. Pitch and pen: first team, light coursework. Sundays would work, Saturdays won’t. Desk-bound: no team, heavy coursework. Saturday work is fine and Sunday is for the coursework.

ImplicationsIn Full Saturdays, what’s true is I’d be letting the garden centre down mid-season; what I’d do is not take the job, or take it only with an agreed exit. In Free and easy, the money and the reference are real; I’d take it now.

SignpostsThe team sheet for the first October match, on the noticeboard, points to Pitch and pen or Full Saturdays. The coursework timetable published in September, on the school portal, points to Full Saturdays or Desk-bound. The band’s first booking, in the group chat, shapes but doesn’t decide.

What I’d do nowRight in every world: ask the garden centre whether Sundays are possible, since that survives three worlds out of four. The bet: say yes to Saturdays now with an honest "I may need to swap in October", which backs Free and easy and Desk-bound. Read the signposts on 5 October.

The move that survives every world, asking about Sundays, is the cheapest output of the exercise and the one nobody would have thought of without building the corner they didn’t expect.

Where it falls down

Four futures becomes fourteen becomes none. Two axes, four boxes, that’s the method, and the box you find implausible gets the same effort as the rest, because it is the one that teaches you most when it starts arriving anyway.

The other failure is scenarios that are never revisited. Without signposts and a date to read them, the four worlds become the office mural: admired, referred to, never checked. Wack’s point was that the scenarios change what you can recognise, and you only recognise what you keep looking for.

Pairs well with

Pre-mortem. When the causes of failure are outside your control, build the worlds instead of trying to prevent them.
Options and Criteria. Judge the options in each world, not just one. An option that wins in three of four is a different thing from one that wins in one.
Stakeholder and Influence Map. The signposts are often people. Who would know first that a world is arriving?