Fig. 2. Control charts showing process time (nonoperative and operative times) for 16 months before initiating the high-throughput perioperative system and then for the subsequent 2 yr. Time advances from left to right across the figure. Each data point is the average for a bin of 10 consecutive times. Note that there are more data points for operative time than for nonoperative time because the latter includes turnover time, and the first case of the day does not have a turnover. The upper control limit (UCL) and lower control limit (LCL) are 3 SDs above and below the mean denoted by the centerline. The UCL, LCL, and centerline are all derived from the complete historic control data set before implementation of the high-throughput process. The purpose of this figure is to compare the performance of the new process to that of the baseline (  i.e. , historic) process. Therefore, it plots historic performance and high-throughput system performance over time, but the concurrent control data are omitted.