Editing Theory of constraints (section)

==Criticism==
Criticisms that have been leveled against TOC include:

===Claimed suboptimality of drum-buffer-rope===
While TOC has been compared favorably to linear programming techniques,<ref>
{{cite journal |doi = 10.1049/me:20020411 |first1 = Mabel |last1 = Qui |first2 = Lawrence |last2 = Fredendall |first3 = Zhiwei |last3 = Zhu |title = TOC or LP? [production control] |journal = Manufacturing Engineer|volume = 81 |issue = 4 | year = 2002| pages = 190–195 |doi-broken-date = 7 December 2024 }}
</ref> D. Trietsch from University of Auckland argues that DBR methodology is inferior to competing methodologies.<ref>{{cite journal | last1 = Trietsch | first1 = D. | year = 2005 | title = From Management by Constraints (MBC) to Management By Criticalities (MBC II) | url = http://ac.aua.am/trietsch/web/MBC_to_MBC_II.pdf | journal = Human Systems Management | volume = 24 | pages = 105–115 | doi = 10.3233/HSM-2005-24109 }}</ref><ref>http://ac.aua.am/trietsch/web/WorkingPaper281.pdf D. Trietsch, From the Flawed "Theory of Constraints" to Hierarchically Balancing Criticalities (HBC), Department of Information Systems and Operations Management, University of Auckland, Working Paper No. 281, May 2004.</ref> Linhares, from the [[Fundação Getúlio Vargas|Getulio Vargas Foundation]], has shown that the TOC approach to establishing an optimal product mix is unlikely to yield optimum results, as it would imply that [[P = NP problem|P=NP]].<ref>{{cite journal |doi = 10.1016/j.ijpe.2009.04.023 |first1 = Alexandre |last1 = Linhares |title = Theory of constraints and the combinatorial complexity of the product-mix decision |journal = International Journal of Production Economics|volume = 121 |issue = 1 | year = 2009| pages = 121–129 }}</ref>

===Unacknowledged debt===
Duncan (as cited by Steyn)<ref name=steyn>
{{cite journal | first = Herman | last = Steyn | title = An Investigation into the Fundamentals of Critical Chain Project Scheduling. | journal = International Journal of Project Management | issue = 19 | year = 2000| pages = 363–369 }}
</ref>
says that TOC borrows heavily from [[System dynamics|systems dynamics]] developed by [[Jay Forrester|Forrester]] in the 1950s and from [[statistical process control]] which dates back to World War II. And Noreen Smith and Mackey, in their independent report on TOC, point out that several key concepts in TOC "have been topics in management accounting textbooks for decades."<ref name=tocma/>{{rp|page=149}} It is also claimed{{Citation needed|date=November 2007}} that Goldratt's books fail to acknowledge that TOC borrows from more than 40 years of previous management science research and practice, particularly from [[program evaluation and review technique]]/[[critical path method]] (PERT/CPM) and the [[Just-in-time (business)|just in time]] strategy.

A rebuttal to these criticisms is offered in Goldratt's "What is the ''Theory of Constraints'' and How Should it be Implemented?", and in his audio program, "Beyond The Goal". In these, Goldratt discusses the history of disciplinary sciences, compares the strengths and weaknesses of the various disciplines, and acknowledges the sources of information and inspiration for the thinking processes and critical chain methodologies. Articles published in the now-defunct Journal of ''Theory of Constraints'' referenced foundational materials. Goldratt published an article<ref name=giants>{{cite journal|last1=Goldratt|first1=Eliyahu M.|title=Standing on the shoulders of giants: production concepts versus production applications. The Hitachi Tool Engineering example.|journal=Gestão & Produção|date=2009|volume=16|issue=3|pages=333–343|doi=10.1590/S0104-530X2009000300002|doi-access=free}}</ref> and gave talks<ref name=giantsvideo>Archived at [https://ghostarchive.org/varchive/youtube/20211211/C3RPFUh3ePQ Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20130303190834/http://www.youtube.com/watch?v=C3RPFUh3ePQ Wayback Machine]{{cbignore}}: {{cite video |author=Eliyahu Goldratt | title=Standing on the Shoulders of Giants | url=https://www.youtube.com/watch?v=C3RPFUh3ePQ}}{{cbignore}}</ref> with the title "Standing on the Shoulders of Giants" in which he gives credit for many of the core ideas of Theory of Constraints. Goldratt has sought many times to show the correlation between various improvement methods.

Goldratt has been criticized on lack of openness in his theories, an example being him not releasing the algorithm he used for the Optimum Performance Training system.<ref name=rahman1998>Rahman, Shams-ur. "Theory of constraints: a review of the philosophy and its applications." International Journal of Operations & Production Management 18.4 (1998): 336-355.
</ref> Some view him as unscientific with many of his theories, tools and techniques not being a part of the public domain, rather a part of his own framework of profiting on his ideas.
According to Gupta and Snyder (2009), despite being recognized as a genuine management philosophy nowadays, TOC has yet failed to demonstrate its effectiveness in the academic literature and as such, cannot be considered academically worthy to be called a widely recognized theory.  TOC needs more case studies that prove a connection between implementation and improved financial performance.<ref name=gupta2009>
Gupta, Mahesh, and Doug Snyder. "Comparing TOC with MRP and JIT: a literature review." International Journal of Production Research 47.13 (2009): 3705-3739
</ref>
Nave (2002) argues that TOC does not take employees into account and fails to empower them in the production process.  He also states that TOC fails to address unsuccessful policies as constraints.<ref name=nave2002>
Nave, Dave. "How to compare six sigma, lean and the theory of constraints." Quality Progress 35.3 (2002): 73-80.
</ref>
In contrast, Mukherjee and Chatterjee (2007) state that much of the criticism of Goldratt's work has been focused on the lack of rigour in his work, but not of the bottleneck approach, which are two different aspects of the issue.<ref>Mukherjee, S. M. and Chatterjee, A. K. (2007). The concept of bottleneck. Working Paper No. 2006-05-01, IIM Ahmedabad</ref>