Vertaile menetelmiä

	Tilastollinen prosessinohjaus (SPC)	Ohjauskaavio
Tieteenala	Koesuunnittelu	Koesuunnittelu
Menetelmäperhe	Process / pipeline	Process / pipeline
Syntyvuosi	1924–1931	1924 (first use); 1931 (seminal book)
Kehittäjä	Walter A. Shewhart	Walter A. Shewhart (Bell Labs)
Tyyppi	Process monitoring and quality control method	Statistical monitoring and control technique
Alkuperäislähde	Shewhart, W. A. (1931). Economic Control of Quality of Manufactured Product. Van Nostrand. ISBN: 978-0873890762	Shewhart, W. A. (1931). Economic Control of Quality of Manufactured Product. Van Nostrand.
Rinnakkaisnimet	SPC, statistical quality control, process control charting, Shewhart control	Shewhart chart, process-behavior chart, SPC chart, quality control chart
Liittyvät	6	6
Tiivistelmä	Statistical Process Control (SPC) is a data-driven quality method that uses statistical techniques — primarily control charts — to monitor a manufacturing or service process over time. By distinguishing natural process variation (common cause) from unusual, actionable variation (special cause), SPC enables practitioners to maintain processes in a stable, predictable state and to detect problems early, before defective output reaches customers.	A control chart is a time-series graph with statistically derived upper and lower control limits that separates the natural, random variation of a process (common cause) from unusual, assignable variation (special cause). Invented by Walter Shewhart at Bell Labs in 1924, control charts remain the foundational tool of Statistical Process Control and are used across manufacturing, healthcare, software, and service industries to monitor whether a process remains stable and predictable over time.