title: Opengroup SOA ontology service vs service interface vs service contract
body: <p>I am trying to understand the definitions in this document.
  <a href="http://www.opengroup.org/soa/source-book/ontologyv2/service.htm" rel="nofollow">http://www.opengroup.org/soa/source-book/ontologyv2/service.htm</a></p>
  
  <p>Their definitions of service, service interface and service contract are either unclear or seem different from what I normally encounter.  </p>
  
  <p>Service:</p>
  
  <blockquote>
    <p>“A service is a logical representation of a repeatable activity that
    has a specified outcome. It is self-contained and is a ‘black box’ to
    its consumers.”</p>
  </blockquote>
  
  <p>Lets say I have a WCF project and it has two Operations
  StoreFront
  +GetPrice
  +AddToCart</p>
  
  <p>The definition says "a repeatable activity".  So is the service StoreFront?  Or do I have two services (GetPrice and AddToCart).</p>
  
  <p>Service Contract:
  Has an "effect" class.   Is the effect "return price"  and " added to cart" ?  </p>