McKinsey Sustainable Futures Lab (SFL): The Complete 2026 Guide
Sustainable Futures Lab is the newest and least understood part of the McKinsey Solve assessment. It contains no maths, has no single right answer, and is scored in a way that catches most candidates off guard. Here is exactly how it works.
Last updated: August 2026 · Written from candidate reports and real past PSG data
- What the Sustainable Futures Lab actually is
- Whether you’ll get SFL at all: 65 vs 85 minutes
- The format, decision by decision
- The five dimensions it measures
- How SFL is scored — and why it isn’t per-answer
- Six mistakes that quietly cost marks
- How to prepare without stealing time from Redrock
- Frequently asked questions
1. What the Sustainable Futures Lab actually is
Sustainable Futures Lab — usually shortened to SFL — is a situational judgement scenario that McKinsey added to the Solve assessment in March 2026. You join an environmental research team working on a sustainability programme, and over roughly 20 minutes you make a sequence of decisions about what the team should prioritise, how to interpret incoming information, and how to handle competing demands.
The critical thing to understand is what SFL is not. It is not an analytical puzzle. There is no calculator, no data table to interrogate, no optimisation to solve. Redrock tests whether you can interpret data accurately under time pressure. Sea Wolf tests whether you can satisfy a set of constraints. SFL tests something entirely different: your judgement.
It is also not a return of the old Ecosystem Building game. That was an analytical food-chain optimisation task, and it was replaced by Sea Wolf back in 2024. Candidates sometimes conflate the two because both involve environmental themes, but they share nothing mechanically. If you are preparing for SFL by practising Ecosystem material, you are preparing for the wrong assessment.
2. Whether you’ll get SFL at all: the 65 vs 85-minute split
Not every candidate sits SFL. Your invitation email tells you which version you have been assigned, and the giveaway is the stated duration.
| Invitation length | Modules you’ll face | Order |
|---|---|---|
| 65 minutes | Redrock + Sea Wolf | Redrock, then Sea Wolf |
| 85 minutes | Redrock + Sea Wolf + Sustainable Futures Lab | Redrock, Sea Wolf, then SFL |
As of mid-2026 most McKinsey offices have moved to the 85-minute version, so you should assume you will face SFL unless your invitation explicitly says 65 minutes. The rollout has been uneven across offices and recruiting cycles, and McKinsey has varied the format by role and region before, so check your own invitation rather than relying on what a friend sat last year.
Note the ordering. SFL comes last, after roughly 65 minutes of dense quantitative work. This matters more than it sounds, and we come back to it in the preparation section.
3. The format, decision by decision
SFL runs for about 20 minutes and presents 13 sequential decisions. Candidates consistently report the same shape:
Ranking and prioritisation tasks
You are given a set of options — actions the team could take, issues that need attention, stakeholders who need a response — and asked to order them. These are usually drag-and-drop. There is no partial credit for getting one item right; what matters is the logic of the whole ordering.
Branching multiple-choice scenarios
A situation develops and you choose how to respond. Crucially, these branch: the scenario you see next depends on what you chose. You cannot go back and you cannot see where a path leads before committing to it.
Interpretation prompts
You are shown information — a colleague’s message, a summary of findings, a stakeholder’s concern — and asked what it means or what should follow from it. These test whether you read carefully or jump to conclusions.
The whole thing runs on a single 20-minute timer. That works out at roughly 90 seconds per decision, which is comfortable if you are decisive and extremely uncomfortable if you are not. Unlike Redrock, there is nothing to calculate, so time pressure here comes entirely from deliberation, not arithmetic.
4. The five dimensions it measures
SFL assesses five distinct traits. Understanding them is the difference between guessing and choosing deliberately.
| Dimension | What it’s really asking |
|---|---|
| Prioritisation | When everything is urgent, can you identify what actually matters most — and does your ordering follow a defensible principle rather than a hunch? |
| Decision-making | Can you commit under uncertainty, without either freezing or acting rashly? |
| Interpretation | Do you read what is actually in front of you, or do you fill gaps with assumptions? |
| Trade-off balance | Do you recognise that gains in one area cost something elsewhere, and do you weigh that openly? |
| Teamwork | Do you work through people, or around them? |
These map closely onto how McKinsey describes what it looks for in consultants generally. That is not a coincidence — SFL is a behavioural screen delivered in game form.
5. How SFL is scored — and why it isn’t per-answer
This is the single most important thing on this page, and it is the thing most candidates get wrong.
Consider what that means in practice. Suppose decision 3 asks you to prioritise, and you place long-term environmental impact above short-term stakeholder satisfaction. Then at decision 9 a stakeholder pushes back and you immediately abandon the long-term position to keep them happy. Individually, either choice is defensible. Together, they describe someone whose stated priorities collapse the moment they meet resistance.
The inverse is also true, and this is the part candidates find counterintuitive: a consistent set of choices that lean slightly the “wrong” way will generally read better than an inconsistent set that includes several individually ideal answers. The assessment is trying to characterise you, not catch you out.
Two practical consequences follow:
Decide what kind of team member you are, before you start. Not a script — a posture. Something like: I weigh evidence before acting, I flag trade-offs openly rather than pretending they don’t exist, and I bring the team with me rather than deciding around them. Then hold it across all 13 decisions, including when the scenario pushes against it.
Don’t try to give the answer you think they want on each screen. Candidates who optimise screen by screen produce exactly the incoherent pattern SFL is built to detect. Consistency is the mechanism being measured.
6. Six mistakes that quietly cost marks
1Treating it as a knowledge test
You don’t need sustainability expertise. Nobody is checking whether you know about carbon accounting. Candidates who try to demonstrate domain knowledge tend to over-engineer their answers and miss the judgement being asked for.
2Arriving at SFL exhausted
SFL comes after 65 minutes of Redrock and Sea Wolf. Most candidates hit it mentally spent and start clicking to get it over with. Judgement degrades faster than arithmetic under fatigue — and this is the module where judgement is the entire score.
3Being agreeable on every screen
Picking the accommodating, non-committal, keep-everyone-happy option each time reads as an inability to make hard calls. Trade-off balance is explicitly one of the five dimensions, and it cannot be demonstrated by someone who never trades anything off.
4Overthinking the ranking tasks
Drag-and-drop prioritisation invites endless reshuffling. It burns your clock and rarely improves the answer. Order by a clear principle, place them, move on.
5Forgetting the branches don’t come back
Once you choose, the scenario moves on and you cannot revisit it. Candidates who mentally relitigate an earlier choice lose focus on the one in front of them.
6Skimming the prompts
Interpretation is a scored dimension. Several prompts contain a specific qualifier — a constraint, a caveat, a deadline — that changes the correct response entirely. Reading at speed is exactly how you miss them.
7. How to prepare without stealing time from Redrock
Be honest about the weighting. Redrock and Sea Wolf are analytically demanding and carry the bulk of the discriminating power in this assessment. SFL is 20 of the 85 minutes and requires no technical skill. It does not deserve half your preparation.
What it deserves is enough exposure that the format holds no surprises. Specifically:
Run through the format two or three times. The goal is not to memorise answers — the scenarios vary. It is to remove novelty, so that on test day you are exercising judgement rather than working out how the interface behaves.
Decide your posture in advance. Write down, in one sentence, how you make decisions. Use it as your tiebreaker whenever two options look equally reasonable. This is what produces the consistency the scoring rewards.
Practise it last in a session. If you practise SFL fresh and sit it exhausted, you have rehearsed the wrong conditions. Do a Redrock and a Sea Wolf first, then hit SFL — that’s the real sequence.
8. Frequently asked questions
How long is the Sustainable Futures Lab?
Approximately 20 minutes, containing 13 sequential decisions. It is the third and final module in the 85-minute version of McKinsey Solve.
Is there any maths in SFL?
No. There are no calculations, no data tables to interpret numerically and no calculator. It is purely a judgement-based scenario.
Will everyone get the Sustainable Futures Lab?
No. Candidates with a 65-minute invitation sit only Redrock and Sea Wolf. Those with an 85-minute invitation also sit SFL. Most offices had moved to the 85-minute format by mid-2026, but check your own invitation.
Is SFL the old Ecosystem Building game?
No. Ecosystem Building was an analytical food-chain optimisation task and was replaced by Sea Wolf in 2024. SFL is a behavioural scenario with no analytical component. They are unrelated.
Are there right and wrong answers in SFL?
Not in the way there are in Redrock. Individual choices are not simply correct or incorrect — your responses are evaluated as a pattern for coherence across the five dimensions. Consistency matters more than any single answer.
Can I go back and change an answer?
No. The scenarios branch based on your choices, so once you commit to a decision you move forward and cannot revisit it.
How much should I prepare for SFL compared to the other modules?
Considerably less. Two or three run-throughs to remove format novelty is usually enough. Redrock and Sea Wolf reward preparation far more heavily and should take the majority of your time.
Practise the Sustainable Futures Lab before test day
Three full SFL simulations built from real past PSG data, with worked explanations for every decision — so the format holds no surprises when it counts.
Get SFL Practice Tests → Or try the free mini-testPSG Solver is an independent preparation resource and is not affiliated with, endorsed by or connected to McKinsey & Company. Assessment formats vary by office, role and recruiting cycle — always check the details in your own invitation.