Conway's law


Conway's law is an adage stating that organizations design systems that mirror their own communication structure. It is named after computer programmer Melvin Conway, who introduced the idea in 1967. His original wording was:
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 organizations 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.
In colloquial terms, it means software or automated systems end up "shaped like" the organizational structure they are designed in or designed for. Some interpretations of the law say this organizational pattern mirroring is a helpful feature of such systems, while other interpretations say it's merely a result of human nature or organizational bias.

Variations

, 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, he said. Summarizing an example in Conway's paper, Raymond wrote:
Raymond further presents Tom Cheatham's amendment of Conway's Law, stated as:
Yourdon and Constantine, in their 1979 book on Structured Design, gave a more strongly stated variation of Conway's Law:
James O. Coplien and Neil B. Harrison stated in a 2004 book concerned with organizational patterns of Agile software development:

Supporting evidence

An example of the impact of Conway's Law can be found in the design of some organization websites. Nigel Bevan stated in a 1997 paper, regarding usability issues in websites: "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."
Evidence in support of Conway's law has been published by a team of Massachusetts Institute of Technology 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 the "product developed by the loosely-coupled organization is significantly more modular than the product from the tightly-coupled organization". The authors highlight the impact of "organizational design decisions on the technical structure of the artifacts that these organizations subsequently develop".
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, and by Syeed and Hammouda at Tampere University of Technology in Finland.