Which of the following is an indication of erratic behavior in a quality control system?

An indication of erratic behavior in a quality control system is characterized by five consecutive points showing differing trends. This behavior suggests that the process is not in a state of control and is exhibiting variation that is not expected. In a quality control context, control charts are used to monitor processes, and consistency in data points typically indicates stability. When there are consecutive points displaying differing trends, it implies that the process may be influenced by unexpected factors or fluctuations, which can lead to potential quality issues.

The other choices reflect stable or consistent behavior in the system. For instance, consistent performance near the target indicates that the process is reliably producing outputs close to the desired level, while all points within control limits suggest that the process variation is random and within acceptable parameters. Stable outputs over time also indicate that the process is controlled and performing predictably. In contrast, option B denotes a lack of predictability and stability in the process, which is a clear sign of erratic behavior.