The consultancies mostly use case studies as assessments at these days. These case studies are representative of real consulting asssignments - they outline a series of issues or problems at a client site and invite you to write a review of them, indicating the impact of them and your recommendations to solve them.They are not rocket science and mostly rely on common sense, being able to filter out what's important, and good, clear written skills (although this can be coached and is therefore less important).As someone who has assessed these, clarity and simplicy is key - these things aren't rocket science, and they are no trick questions - they don't want to catch you out - more to see what you are capable of.You may be asked to give a presentation on your findings, or on a separate topic which you may or may not be informed of in advance - read the business papers of a good paper for a couple of days beforehand so that you're up to date with what is topical.Finally, you might need to do some numerical reasoning tests - do a google search to find these and some short case studies.The most important thing is to be yourself - the interview and personality fit is the most important part of it all. Good luck.
