title: Diagram Type for Service Connections?
body: <p>Just wondering what's the correct UML Diagram type to show Service Connection? Essentially saying that "Client A needs a function GetFoo that needs to return items whose quantity is bigger than 20" and "Client B needs a function GetFoo that returns all items"?</p>
  
  <p>A Component Diagram looks correct, but already very concrete in terms of types and very vague in terms of single functions. Composite Structure maybe?</p>
  
  <p>Eventually this is used during planning to decide which functions a service actually needs to have (e.g., an inner GetFoo and two outer GetHeavyFoo/GetAllFoo functions)</p>