Tell me about a time when variance is reported without identifying the business driver. What did you do?

I first confirmed the facts and contained the immediate impact. Next, I reviewed purchase data, standard price, actual price, and variance bridge and coordinated the action to separate price, quantity, mix, exchange-rate, and timing effects. After verifying the result, I summarized the root cause, preventive control, owner, and follow-up plan so the issue would not recur.