A tool used to determine the boundaries of acceptable variation in a process, this application typically takes input such as sample averages, standard deviations, and sample sizes. It then calculates upper and lower bounds, often visualized on a control chart, which help distinguish between common cause variation (inherent to the process) and special cause variation (due to assignable factors). For example, in manufacturing, it might analyze the diameter of produced parts to identify when adjustments are needed.
Establishing these boundaries provides a framework for monitoring process stability and identifying potential problems early. This proactive approach reduces waste, improves quality, and contributes to overall efficiency. Historically rooted in statistical process control, these calculations have become an indispensable part of quality management in various sectors, from healthcare to finance.
