1. A method of defining an interface of a service in a service-oriented architecture environment, said method comprising: a computer receiving definitions of atomic tasks of a first operation included in a first service, said first operation being a request or a response; said computer assigning unique identifiers corresponding to said atomic tasks; said computer receiving a sequence map required to implement said first service, wherein said received sequence map includes a sequence of said unique identifiers corresponding to a sequence of said atomic tasks of said first operation; and said computer at a runtime dynamically and automatically generating a first interface of said first service to define said first service by reading said sequence of said unique identifiers in said received sequence map and assembling said sequence of said atomic tasks based on said read sequence of said unique identifiers.