Greetings: At the outset, I should make it clear that I am entirely new to service-orientation (all I have done is read some of Thomas Erl's book "Service-Oriented Architecture")
I am having some difficulty understanding the basic concept of an "operation". Erl characterizes an operation as a "unit of work" and makes the following statement: "The processing (of an operation) consists of sending and receving SOAP messages". He also writes that "An operation is defined mostly by the messages it processes". (my underline) I am not entirely sure if I can formulate a specific question. I am unclear to what extent operations do things other than process messages (I am aware this question might reveal a fundamental misunderstanding on my part). I am also inclined to ask a question of the form "Do messages determine the content of operations or do operations determine the content of messages?", if you can make sense of that way of framing things. I am also interested in opinions as to how to make sense of this statement by Erl: "A service groups a collection of related operations?". Related in what sense? In short. I am interested in any views on the fundamental nature of an operation and its relation to messages and services. You should know that while I am exceedingly comfortable with abstract, concept-level explanations, I have a very limited knowledge of "technology" terms. Thanks in advance for any thoughts, Andrew Herbst
