เปรียบเทียบวิธี

	ทฤษฎีข้อจำกัด (Theory of Constraints - TOC)	กฎของลิตเติล (L = λW)	Six Sigma DMAIC	การทำแผนที่กระแสมูลค่า
สาขาวิชา	การจัดการคุณภาพ	การวิจัยดำเนินงาน	การจัดการคุณภาพ	การจัดการคุณภาพ
ตระกูล	Process / pipeline	Regression model	Process / pipeline	Process / pipeline
ปีกำเนิด	1990	1961	2014	1999
ผู้ริเริ่ม	Eliyahu Goldratt	John D. C. Little	Motorola; Pyzdek & Keller	Mike Rother & John Shook
ประเภท	Continuous improvement framework	Exact queueing identity	Structured process improvement methodology	Visual process analysis tool
แหล่งต้นตำรับ	Goldratt, E. M. (1990). Theory of Constraints. North River Press. ISBN: 978-0-88427-166-6	Little, J. D. C. (1961). A proof for the queuing formula: L = λW. Operations Research, 9(3), 383–387.	Pyzdek, T., & Keller, P. (2014). The Six Sigma Handbook (4th ed.). McGraw-Hill. ISBN: 978-0-07-184053-9	Rother, M., & Shook, J. (1999). Learning to See: Value Stream Mapping to Add Value and Eliminate Muda. Lean Enterprise Institute. ISBN: 978-0-9667843-0-5
ชื่อเรียกอื่น	TOC, Constraint Management, Bottleneck Theory, Kısıtlar Teorisi	L = λW Theorem, Little's Theorem, Little's Result, Little Yasası	DMAIC Framework, Six Sigma Process Improvement Cycle, Define-Measure-Analyze-Improve-Control, Altı Sigma DMAIC	VSM, Material and Information Flow Mapping, Lean Flow Mapping, Değer Akış Haritalama
ที่เกี่ยวข้อง	3	3	3	3
สรุป	The Theory of Constraints (TOC) is a management philosophy and continuous improvement framework introduced by Eliyahu Goldratt in his 1984 novel The Goal and formalized in his 1990 book. TOC holds that every system has at least one constraint — a bottleneck that limits the system's overall throughput — and that systematically identifying and addressing that constraint is the most effective lever for improving performance. It is widely applied in manufacturing, project management, supply chains, and service operations.	Little's Law is a fundamental theorem in queueing theory that relates the long-run average number of items in a stable system (L) to the long-run average arrival rate (λ) and the long-run average time an item spends in the system (W), expressed as L = λW. Introduced and rigorously proved by John D. C. Little in 1961, the law holds for virtually any stable stochastic system, requiring no assumptions about arrival distributions, service distributions, or queue disciplines.	Six Sigma DMAIC is a data-driven, five-phase process improvement methodology — Define, Measure, Analyze, Improve, and Control — used to reduce defects and process variation to fewer than 3.4 defects per million opportunities. Originating at Motorola in the 1980s and systematized by practitioners including Pyzdek and Keller, it is widely adopted in manufacturing, healthcare, finance, and service industries seeking sustained quality gains.	Value Stream Mapping (VSM) is a lean management technique used to visualize, analyze, and improve the flow of materials and information required to bring a product or service from raw input to customer delivery. Introduced by Mike Rother and John Shook in their 1999 workbook Learning to See, VSM draws on the Toyota Production System tradition to expose waste, delays, and non-value-adding activities across the entire production value stream.