今天在msn上跟chuanbo討論component design，說到component和class有什么具體的區別。現在找到了一篇講組件設計的小文章：
http://www.agilemodeling.com/artifacts/componentDiagram.htm
開頭的那段話對上面那個問題尤其有用吧：
Component diagrams are particularly
useful with larger teams.? Your initial architectural
modeling efforts during cycle 0 should focus on identifying the initial
architectural landscape for your system.? UML component
diagrams are great for doing this as they enable you to
model the high-level software components, and more
importantly the interfaces to those components.? Once
the interfaces are defined, and agreed to by your team,
it makes it much easier to organize the development
effort between subteams. You will discover the need to
evolve the interfaces to reflect new requirements or
changes to your design as your project progresses,
changes that need to be negotiated between the subteams
and then implemented appropriately.