CONTROL CHART: HOW TO CREATE IT

摘要

Control Chart is a graph used to study how a process changes over time. Data are plotted in time order. A Control Chart always has a central line (CL) for the average, an upper line for the upper control limit (UCL) and a lower line for the lower control limit (LCL). These lines are determined from historical data. By comparing current data to these lines, you can draw conclusions about whether the process variation is in control or is out of control, affected by special causes of variation.