Context:
This pattern is a building block for other patterns in the language, including Organization Follows Market, Developer Controls Process, Architect Also Implements, Engage QA, Engage Customers, Buffalo Mountain, and others. This pattern may also apply to circulation realms outside the project, such as Firewalls, and many others.
Forces:
Proper communication structures between roles are key to organizational success.
Communication can't be controlled from a single role; at least two roles must be involved.
Communication patterns can't be dictated; some second-order force must be present to encourage them.
Communication follows semantic coupling between responsibilities.
Solution:
Give people job responsibilities that suggest the appropriate interactions between roles (see also Move Responsibilities).
Physically collocate people whom you wish to have close communication coupling (this is the dual of the pattern Organization Follows Location).
Tell people what to do and with whom they should interact; people will usually t ry to respect your wishes if you ask them to do something reasonable that is within their purview and power.
Resulting Context:
The goal is to produce an organization with higher overall cohesion, with sub-parts that are as internally cohesive and externally de-coupled as possible.
Design Rationale:
This follows an Alexandrine pattern [Alexander 98] of the same name, and has strong analogies to the rationales of ``House Cluster'' [Alexander 37]. The same rationale can be found in Thomas Allen. Note that Move Responsibilities is a closely related pattern.
See related notes in the Rationale for Gatekeeper.
Next: Move Responsibilities