You are employed as a Quality Control Supervisor or Manager for a biopharmaceutical company. You have four QC analysts who report to you. The QC analysts work in the laboratory and perform testing of drug substance (API) and Drug Product to support release and stability programs. Over a period of time, you observe that one of the QC analysts has output that greatly exceeds the other three analysts. You cannot fathom why this output is higher than the others. How should you proceed?