Control charts for quality Assurance
Title - Control charts for Quality Assurance Description-: Control charts are graphs used to study how a process changes over time. Data is plotted in time order. A control chart always has a central line for the average, an upper line for the upper control limit and a lower line for the lower control limit. These three lines are determined from historical data. By comparing current data to these lines, you can draw conclusions about whether the process variation is consistent (in control) or is unpredictable (out of control, affected by special causes of variation). Variable data uses two control charts. The top chart monitors the average, or the centering of the distribution of data from the process. The bottom chart monitors the range, or the width of the distribution. If your data were shots in target practice, the average shows the shots clustering. The range shows how tight they are clustered. When To Use: When controlling o...