The abbreviation SPC from Six Sigma stands for Statistical Process Control. It is a tool used to monitor and assess processes regarding their performance and effectiveness. SPC ensures that processes operate in a controlled manner, meaning they are stable and deliver the intended performance, while also identifying processes that are out of control so that corrective actions can be taken. Statistical process control uses quality control charts—known as control charts—to visualize the progress of a process and the development of critical input and/or output variables.