Conway's law

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Conway's law is an adage named after computer programmer Melvin Conway, who introduced the idea in 1967.[1] It states that

organizations which design systems ... are constrained to produce designs which are copies of the communication structures of these organizations.

— M. Conway[2]

The law is based on the reasoning that in order for a software module to function, multiple authors must communicate frequently with each other. Therefore, the software interface structure of a system will reflect the social boundaries of the organization(s) that produced it, across which communication is more difficult. Conway's law was intended as a valid sociological observation, although sometimes it's used in a humorous context. It was dubbed Conway's law by participants at the 1968 National Symposium on Modular Programming.[3]


Eric S. Raymond, an open-source advocate, restated Conway's law in The New Hacker's Dictionary, a reference work based on the Jargon File. The organization of the software and the organization of the software team will be congruent, he said. Summarizing an example in Conway's paper, Raymond wrote: "If you have four groups working on a compiler, you'll get a 4-pass compiler."[4][5]

James O. Coplien and Neil B. Harrison stated:

If the parts of an organization (e.g., teams, departments, or subdivisions) do not closely reflect the essential parts of the product, or if the relationship between organizations do not reflect the relationships between product parts, then the project will be in trouble ... Therefore: Make sure the organization is compatible with the product architecture.[6]

One can also see the impact of Conway's Law in design of corporate websites. Nigel Bevan, a usability expert, stated in 1998: "Organisations often produce web sites with a content and structure which mirrors the internal concerns of the organisation rather than the needs of the users of the site."[7] A similar effect may be found when websites undergo design by committee.[citation needed]

Supporting evidence[edit]

Evidence in support of Conway's law has been published by a team of Massachusetts Institute of Technology (MIT) and Harvard Business School researchers who, using "the mirroring hypothesis" as an equivalent term for Conway's law, found "strong evidence to support [the] mirroring hypothesis", and that "significant differences in [product] modularity" were "consistent with a view that distributed teams tend to develop more modular products".[8]

Additional and likewise supportive case studies of Conway's law have been conducted by Nagappan, Murphy and Basili at the University of Maryland in collaboration with Microsoft,[9] and by Syeed and Hammouda at Tampere University of Technology in Finland.[10]

See also[edit]


  1. ^ Conway, Melvin. "Conway's Law". Mel Conway’s Home Page. Archived from the original on 2019-09-29. Retrieved 2019-09-29.
  2. ^ Conway, Melvin E. (April 1968), "How do Committees Invent?", Datamation, 14 (5): 28–31, retrieved 2015-04-10
  3. ^ Yourdon, E. N., and Constantine, L. L. Structured Design (Prentice Hall, 1978), p. 400
  4. ^ Raymond, Eric S. (October 1996). The New Hacker's Dictionary (3rd ed.). Cambridge, Massachusetts: MIT Press. p. 124. ISBN 978-0-262-68092-9. Conway's Law: prov. The rule [...] originally stated as "If you have four groups working on a compiler, you'll get a 4-pass compiler".
  5. ^ Eric S. Raymond, Conway's Law, retrieved 2012-06-18
  6. ^ Coplien and Harrison (July 2004). Organizational Patterns of Agile Software Development. ISBN 978-0-13-146740-8.
  7. ^ Bevan, Nigel (April 1998). "Usability Issues in Web Site Design" (PDF). Archived from the original (PDF) on 2018-02-19. Retrieved 2018-02-19.
  8. ^ "Exploring the Duality between Product and Organizational Architectures : A Test of the "Mirroring" Hypothesis" (PDF). Retrieved 15 January 2015.
  9. ^ Nachiappan Nagappan, Brendan Murphy & Victor Basili, 2008, "The Influence of Organizational Structure On Software Quality: An Empirical Case Study," ACM TechReport MSR-TR-2008-11, see [1], accessed 9 March 2015.
  10. ^ Syeed, M. M. Mahbubul; Hammouda, Imed (2013). "Socio-technical Congruence in OSS Projects: Exploring Conway's Law in FreeBSD". Open Source Software: Quality Verification. IFIP Advances in Information and Communication Technology. 404. pp. 109–126. doi:10.1007/978-3-642-38928-3_8. ISBN 978-3-642-38927-6.

Further reading[edit]

  • Alan MacCormack, John Rusnak & Carliss Baldwin, 2012, "Exploring the Duality between Product and Organizational Architectures: A Test of the 'Mirroring' Hypothesis," Research Policy 41:1309–1324 [earlier Harvard Business School Working Paper 08-039], see [2], accessed 9 March 2015.
  • Lise Hvatum & Allan Kelly, Eds., "What do I think about Conway's Law now? Conclusions of a EuroPLoP 2005 Focus Group," European Conference on Pattern Languages of Programs, Kloster Irsee, Germany, January 16, 2006, see [3], addressed 9 March 2015.
  • Lyra Colfer & Carliss Baldwin. "The Mirroring Hypothesis: Theory, Evidence and Exceptions." Harvard Business School Working Paper, No. 16-124, April 2016. (Revised May 2016.) See [4], accessed 2 August 2016.