Read First: Operation, Object Type, Method Read Next: receivesDispatchFrom/dispatchesOperationTo Gives methods that can achieve the goals of an operation. Non-object-oriented operations will have at most one method. Object-oriented operations can have many methods, which is called polymorphism. For example, the operation Fill Order may different depending on the order being filled. In the polymorphic case, one of the methods must be chosen when an operation is invoked on an object. See receivesDispatchFrom/dispatchesOperationTo. The definition of operation applies whether or not an operation is polymorphic. For example, an operation Fill Order is a request to fill an order, whether there is one way to do it or many. If methods are added or removed, or even if operation changes from object-oriented to non-object-oriented, the resulting event type is unaffected. Likewise, none of the rest of an operation's "interface is affected, namely its inputs, outputs, preconditions, postconditions. This also means that any uses of the operation are unaffected by whether an operation is polymorphic or not (see initiates/initiatedBy). Read First: Operation, Object Type, Method Read Next: receivesDispatchFrom/dispatchesOperationTo