What would you say has been your biggest mistake?

Choose your biggest mistake carefully when answering this question. Pick an example when you were able to retrieve the situation and turn the result around. We all make mistakes but you need to cite one that turned out well or at least provided you with a valuable learning experience. If you can prove that you turned the situation around, so much the better. One good example I heard was when a team lost a contract for highly profitable work because they missed the deadline for bidding for the contract. They learned a lesson, established a much tighter checking process on dates and work plans… and managed to win the contract back again the next time it was on offer. Every team in the unit benefited from the original mistake because they all used the new system and were more effective as a result.