From The Mythical Man-month, a description of a law first described by Mel Conway. Effective designs require flexible organizations.
Because the design that occurs first is almost never the best possible, the prevailing system concept may need to change. Therefore, flexibility of organization is important to effective design. (Link)
There are other things to take away as well — for instance, an effective design team is always biased from day one: the organization of the team pre-determines the range of options for the product.
Given any design team organization, there is a class of design alternatives which cannot be effectively pursued by such an organization because the necessary communication paths do not exist. Therefore, there is no such thing as a design group which is both organized and unbiased. (Source)