What is meant by statistical throughput control, and how does it differ from statistical process control? Could one use SPC tools (i.e., control charts) for throughput tracking?

Statistical throughput control (STC) is a method used to monitor, track, and control the performance, efficiency, and productivity of a process by measuring the rate at which input is transformed into output. Throughput is considered as the output per unit of time, which is generally measured in terms of goods or services produced.

Statistical process control (SPC) is a quality control method used to monitor, track, and control variation in a process by using statistical techniques. This is achieved by collecting data from the process, analyzing it, and comparing it against control limits to ensure that the process is operating within the specified range. SPC tools (such as control charts) help to detect deviations and identify potential causes of variability in the process.

The main difference between statistical throughput control and statistical process control is their focus area. STC is primarily concerned with measuring and monitoring the throughput (output per unit of time) of a process to ensure its efficiency and productivity, while SPC is focused on controlling variation in the process and maintaining product quality. STC helps to optimize resource utilization, ensure the timely delivery of goods or services, and improve overall process performance. On the other hand, SPC aims to reduce process variability, minimize waste, and enhance the quality of the product.

Although SPC tools (such as control charts) are primarily designed to monitor and control process variability, they can be adapted to track throughput as well. Control charts can be created for throughput data to monitor changes over time and identify potential issues related to productivity, efficiency, and process performance. For example, a control chart could be constructed for the throughput of a production line, with upper and lower control limits established based on historical throughput data. If the throughput consistently falls outside of these control limits, it may indicate a problem with the process that requires further investigation and intervention. In conclusion, SPC tools can be used for throughput tracking, provided that they are customized to capture throughput data and establish appropriate control limits for the process being monitored.