Welcome to your interview.
The question is on your right: Root Cause of Efficiency Drop. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
During a live analysis exercise, how would you identify the root cause of a sudden 15% drop in operational efficiency within a key project department at Qinetiq?