ARL statistics

ARL stands for Average Run Length, a statistical measure used in quality control and process monitoring. It indicates the average number of samples taken before an alarm is triggered, signaling a potential problem, such as a deviation from a process standard. A longer ARL means that the system can detect issues less frequently, which might be suitable for stable processes, while a shorter ARL provides quicker alerts but may lead to false alarms in normal variations. Understanding ARL helps in optimizing monitoring systems to balance sensitivity and reliability in detecting changes.