Σύγκριση μεθόδων

	Διάγραμμα Ελέγχου	Ανάπτυξη Λειτουργίας Ποιότητας
Πεδίο	Πειραματικός Σχεδιασμός	Πειραματικός Σχεδιασμός
Οικογένεια	Process / pipeline	Process / pipeline
Έτος προέλευσης	1924 (first use); 1931 (seminal book)	1966 (Japan); popularised in the West ~1988
Δημιουργός	Walter A. Shewhart (Bell Labs)	Yoji Akao
Τύπος	Statistical monitoring and control technique	Structured quality planning and product design method
Θεμελιώδης πηγή	Shewhart, W. A. (1931). Economic Control of Quality of Manufactured Product. Van Nostrand.	Akao, Y. (Ed.). (1990). Quality Function Deployment: Integrating Customer Requirements into Product Design. Productivity Press. ISBN: 978-0915299416
Εναλλακτικές ονομασίες	Shewhart chart, process-behavior chart, SPC chart, quality control chart	QFD, House of Quality, customer-driven engineering, voice of the customer matrix
Συναφείς	6	4
Σύνοψη	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.	Quality Function Deployment (QFD) is a structured method for translating customer needs — the voice of the customer — into specific technical requirements at every stage of product or service development. Originating in Japan in the 1960s, QFD uses a matrix-based tool called the House of Quality to make customer priorities visible, link them to engineering parameters, expose trade-offs, and maintain focus on what customers actually value throughout the design process.