Your potential employer will want to know what you accomplished, and what you didn't, in your current or last position.
The best way to respond is to give an example of something you accomplished that is directly related to the job you are interviewing for. Review your resume and review the job posting. Find the best match and use that to show how what you accomplished will be beneficial to the company you are interviewing with.
If you wrote a targeted cover letter when applying for the job use the information you included to create your response. For example, if you are interviewing for a job at a school where you will need to manage student registration, explain to the interviewer how you registered students for courses, designed and managed registration software, and solved customer problems.
If you didn't fail at anything, say so. If you can think of an example, be sure that it's a minor one and turn it into a positive. For example, if you were working on a project that was behind deadline, explain to the interviewer how you adjusted the workload and the timeline to get back on track and ahead of schedule.
Sorry to tell you, but your question makes ***no*** sense at all.