1) Make sure that you've prepared everything: A story about yourself, motivational questions and the three main stories - one for each of the skills the company wants to test you on - Personal Impact, Leadership, Achievement. Also, don't forget about your questions to the interviewer - you'd rather have an interesting conversation and score some point instead of a simple Q&A session
More details here: Typical McK PEI question for each dimension
and here: "Why consulting?" & "Why Mckinsey/BCG/Bain" Questions
2) Then go through each story and think of the additional questions the interviewer may ask. It’s important since additional questions will take up to 50% of the interview. Try to remember the main details and facts and make sure that you know how to explain the key concepts quickly. Test your stories with your friends, ideally consultants, and ask for their feedback. There can be multiple groups of additional questions:
- The interviewer may be interested in details about the context
- He may want to check whether this was your effort or more sort of a team effort.
- “Have you faced any difficulties while implementing your solution?”- Typically an interviewer would like you to tell him how you’ve overcome those difficulties.
- Your interviewer will check how real your story is. You should be ready to provide even more granular actions, key milestones and a breakdown of potential effects.
3) Now work on 3-6 backup stories. During your interviews, you can then use these stories or adapt these stories to the additional questions your interviewer asks you.
You may be interested, why you need to prepare several stories for each question? At the end of the day, it's not that easy to come up with all of these stories. I've answered here: Repeating Fit Interview Stories
4) Next step is talking to consultants. I recommend doing a couple of mock interviews, both case+fit. You can connect with consultants via friends, company events or even LinkedIn. Consultants are entirely opened to share their experiences, but the biggest problem will be the lack of time. Sometimes you’ll need to send a kind reminder to your request, but it pays off.
Feel free to reach me - I have a separate session for working on PEI and crafting your stories with a lot of tips and consulting tools.