Sustainable Future Lab · sourced guide
McKinsey Solve game: read the Lab before you act.
Start by identifying the format in front of you. Then keep three things separate: what the brief asks for, what the evidence supports, and what you are only assuming.
There are two reported Lab formats. Keep them apart.
CORROBORATED — The September fidelity refresh records a 20-minute format: introductory screens, a ranking of four early priorities, twelve single-choice decisions and a consequence page after each answer. It records no back navigation. These are candidate-reported details, not a published McKinsey specification. Source and context.
REPORTED — A September 2026 candidate describes a different format with onboarding, four researchers, four workstations and Day 1 through Day 3. The account supports that broad shape; it does not verify every control a preparation provider describes. Source and context.
REPORTED — Secondary sources describe the team Lab as about 30 minutes. The fidelity contract treats this timing as reported; the linked candidate account does not give a duration. Do not infer your assigned Lab from the total invitation length alone. Source and context.
VERIFIED — McKinsey says the invitation states your assessment length and each task begins with an untimed tutorial. Read the assigned task’s instructions before applying a routine learned elsewhere. Source and context.
For ranking and decisions, turn the brief into a rule.
Practice method: write a short ordering rule before you rank anything. Identify dependencies, deadlines and the cost of acting without information. For each later decision, check whether new evidence changes that rule.
Original CaseStar exercise
The dependency beats the attractive deadline
A field team must validate its water readings before submitting a permit. Community outreach can use the same checked results. The permit deadline is close. Which comes first: submit the permit, validate the readings, or start outreach?
This is a CaseStar teaching example. It has no claimed connection to a live question or hidden marking rule.
Show the working
Validate the readings first. The briefing says the permit needs valid measurements. Sending invalid readings earlier does not satisfy that dependency.
Then prepare the permit, with outreach after the evidence is usable. If a later update says validation is already complete, change the order. The lesson is to follow the dependency, not memorise a preferred sequence.
When reviewing practice, read the consequence alongside the evidence available when you chose. A bad outcome alone does not prove the decision was unreasonable; a good outcome does not excuse an unsupported assumption.
For the team Lab, distinguish a fact from a guess.
CASESTAR PRACTICE CHOICE — CaseStar’s team practice uses Explore, Assign, Support and Reflect, limited requests and its own mission-based feedback. The fidelity register marks these detailed phases and request budgets as reconstructed practice choices. They are not verified live-test rules. Source and context.
Practice method: ask a question that could change your placement decision. Keep the answer beside the person or station it describes. When you give a reason for a move, check that the reason is backed by something you actually read.
Original CaseStar exercise
One answer does not establish every personal state
A researcher tells you they can help with sampling. You assign them to the sampling station. Later you must assess their morale. Does their earlier answer establish that morale is high?
Show the working
No. You learned where the researcher can contribute, not how they feel. An honest review distinguishes a supported placement from an unsupported morale rating. Ask about morale if the practice rules and remaining requests allow it; otherwise acknowledge the gap.
UNKNOWN — The relative weight of information gathering, staffing choices and dialogue in McKinsey’s result is not established here. CaseStar’s review explains its own practice model; it is not a reconstruction of a recruiter’s score. Source and context.
Use the review to change one habit.
- Play the sample without trying to reverse-engineer a score.
- Find one choice where your reason went beyond the evidence.
- State what you would need to know before making that choice again.
- Try a fresh scenario and check whether you notice the same gap.
CaseStar feedback can explain an original practice paper. It cannot tell you whether you will advance. For the real sitting, your invitation, tutorial and recruiter take precedence.
Common questions
How long is Sustainable Future Lab?
CORROBORATED — the September fidelity refresh records a 20-minute ranking-and-decisions format. REPORTED — secondary descriptions put the newer team Lab at about 30 minutes; the linked candidate account does not establish that duration. VERIFIED — your invitation gives your own assessment length.
Are the two Lab formats the same?
No. CORROBORATED — the earlier format is described as a priority ranking followed by decisions and consequences. REPORTED — a September 2026 candidate describes onboarding and three days with four researchers and four workstations. That account does not establish exact request limits, phase names or scoring.
Can I choose which Lab I get?
UNKNOWN — these sources do not establish a candidate-controlled choice. Use the invitation and the tutorial for the assessment assigned to you. CaseStar lets you choose a practice format; that is a product feature.
Is there one correct leadership style?
UNKNOWN — McKinsey’s hidden scoring rules are not established by these sources. In CaseStar’s practice model, read the mission, check what you actually learned, and choose an action you can support with that evidence.
What is free?
CaseStar’s linked Lab brief offers a free sample. It is original practice with its own feedback. Read the brief for current full-sitting eligibility; this guide does not promise unrestricted full sittings.
Sources and limits
- McKinsey: Solve assessment overview and integrity rules
- McKinsey: Solve FAQ (September 2026)
- June 2026 candidate discussion: earlier Solve format
- September 2026 candidate account: researchers, workstations and three days
- Secondary Lab walkthrough: reported duration and reconstructed controls
- CaseStar: what changed in McKinsey Solve in 2026 (dated change log with confidence labels)
CaseStar (casestar.io) is an independent practice platform for consulting recruiting: timed McKinsey Solve simulators, including Red Rock, and voice case interviews. It is not affiliated with McKinsey & Company.
McKinsey publishes only a broad description of Solve. Details labelled as candidate-reported come from debriefs and can differ between candidates, regions and test versions. Worked examples on this page are original CaseStar exercises, not assessment questions. Your invitation and recruiter take precedence.