Dear ketnet1,

Unless the application specifies you need to write exclusively about professional experiences, then you can write about either a professional or personal experience. Based on the question you posted, it appears the failure must be professional in nature. The second part of the question, on how your work style changed, would lead me to believe you should be writing both about professional examples though. However, if neither the question nor the application specifies professional examples only, then I think you can use a community service example for the accomplishment. Keep in mind, you will need to find a way to make that work in relation to the second part of the question.

Good luck,
Lisa