How can messaging be used to invoke a procedure in another application?
Use a Command Message to reliably invoke a procedure in another application.
There is no specific message type for commands; a Command Message is simply a regular message that happens to contain a command. In JMS, the command message could be any type of message; examples include an ObjectMessage containing a Serializable command object, a TextMessage containing the command in XML form, etc. In .NET, a command message is a Message with a command stored in it. A Simple Object Access Protocol (SOAP) request is a command message.
... Read the entire pattern in the book Enterprise Integration Patterns