Written Case Interviews: What They Test and How to Prepare

Written case interviews are used by BCG and others. Here’s what they test, how they’re scored, and how to prepare effectively.

A Different Kind of Challenge

If you’ve been prepping exclusively for verbal case interviews, a written case can throw you completely off balance. Several consulting firms use them, including BCG, Roland Berger, and some regional offices of other top firms. The format is different enough from standard cases that it deserves its own preparation strategy.

In a written case, you typically receive a packet of information: data tables, charts, market research excerpts, customer interviews, financial statements, and sometimes even email threads between fictional executives. You get a set amount of time, usually 60 to 90 minutes, to analyze the material and produce a written recommendation. Some firms then have you present your findings to an interviewer.

It’s not harder or easier than a verbal case. It’s just different. And the skills it tests are ones that matter enormously in actual consulting work.

What Written Cases Are Really Testing

Your Ability to Process Information Quickly

The data packet is intentionally overwhelming. There’s more information than you could possibly use, and some of it is irrelevant. The test is whether you can identify what matters, ignore what doesn’t, and build a coherent analysis from messy inputs. This is literally what consultants do every day on client projects.

Your Written Communication Skills

Consultants spend a shocking amount of time writing. Presentations, memos, emails to clients, internal updates. Your ability to communicate clearly in writing is a core professional skill, and the written case lets firms evaluate it directly.

Your Independence

In a verbal case, the interviewer guides you with hints and follow-up questions. In a written case, you’re on your own. Nobody is going to tell you if you’re going down the wrong path. You need to self-correct, manage your own time, and make judgment calls about what to prioritize.

How to Structure Your Time

Time management is probably the single biggest differentiator in written cases. Here’s a framework that works for a 90-minute case:

The first 15 to 20 minutes should be spent reading and organizing. Go through the entire packet once to understand the scope. Don’t start analyzing yet. Just figure out what you’ve been given and what question you’re being asked to answer. Make notes about which exhibits seem most relevant.

The next 40 to 50 minutes are for analysis. This is where you dig into the data, run calculations, identify patterns, and build your argument. Focus on the two or three most important insights rather than trying to address everything in the packet. Depth beats breadth in a written case.

The final 20 to 25 minutes are for writing and organizing your deliverable. Whether it’s a memo, a slide outline, or a structured recommendation, give yourself enough time to write it clearly. A brilliant analysis that’s poorly communicated will score lower than a good analysis that’s presented well.

Structuring Your Written Output

Lead With Your Recommendation

Don’t build up to your conclusion. State it upfront. “We recommend that Company X pursue Option B: expanding into the mid-market segment through a targeted acquisition.” Then spend the rest of your document supporting that recommendation with evidence and analysis.

This mirrors how consulting deliverables work in practice. Senior clients don’t want to read through ten pages of analysis before finding out what you think they should do. They want the answer first, then the supporting logic.

Use a Clear Framework

Organize your analysis into three or four distinct sections. Each section should address a different aspect of the problem: market attractiveness, competitive position, financial feasibility, implementation risks. Use headers. Use bullet points sparingly but effectively. Make it scannable.

Show Your Math

Don’t just state conclusions. Show how you got there. “Revenue would increase by approximately $15M based on capturing 5% of the $300M mid-market segment” is much stronger than “Revenue would increase significantly.” The interviewer wants to see your reasoning, not just your conclusions.

Acknowledge Uncertainty

Great candidates identify what they don’t know and flag it explicitly. “This analysis assumes customer acquisition costs remain stable, which may not hold if competitors respond aggressively. Further research would be needed to validate this assumption.” This shows maturity and intellectual honesty.

Common Written Case Pitfalls

Trying to use every piece of data in the packet is the most common mistake. It leads to unfocused analysis and wasted time. Remember, the extra data is there deliberately. Knowing what to ignore is part of the test.

Running out of time is the second most common problem. Candidates get absorbed in analysis and realize they only have five minutes left to write their recommendation. Set a timer. Force yourself to transition from analysis to writing even if you feel like you could dig deeper.

Writing too much is surprisingly common too. A concise, focused two-page memo is better than a sprawling five-page document that tries to cover everything. Edit ruthlessly. Every sentence should earn its place.

Preparing for Written Cases

Practice with real business cases from case competitions or business school case libraries. Set a timer, print out the materials (yes, print them, because you’ll likely receive a physical packet), and work through the analysis as if it were the real thing.

Focus especially on your writing speed and clarity. If you can produce a clean, structured one-page recommendation with supporting analysis in 20 minutes, you’re in good shape. If it takes you 40 minutes, practice more. The analysis is important, but the output is what gets evaluated.