We have now establisDoes hourly testing volume adequately explain the variation experienced during those time frames? A Yes, when stratified by hours with peak volume, the process for the peak hours is in control, indicating that there are no "special causes" that would indicate one or more additional root causes. B Yes, when stratified by hour with peak volume, all of the outliers occur in the segment of data representing the peak volume hours of the day. C No, there are also more processing defects associated with the peak volume hours, and those errors add significant time to resolve. D No, there are also staffing and people-driven quality issues associated with certain shifts. E No, there are also centrifuge bottleneck issues that occur independently and which have a major impact on process flow.hed a link between the hour of day and the highest values of turnaround time. Which of the following statements best incorporates what we have learned into a theory of root cause? A Hour of day is the root cause of high turnaround times. B Hour of day is the root cause of high turnaround times, but only on certain days. C Hour of day is one of