UML Weekend Crash Course™ - To Parent Directory

196
Saturday Evening
pointing toward the receiver, in this case the OrderFulfillmentClerk. Label the event arrow
with the sequence number and operation. Figure 19-4 shows both the message sent in
step 1 and the answer received in step 2. The return arrow uses a dashed line style arrow.
Label the return with the sequence number and the data being returned.
:OrderFullfillment Clerk
1 : getOrderNbr():int
2 : return 12345678
:System
Figure 19-4 Modeling a synchronous event and the reply
In the second step of the flowchart, the System tries to find the Order in the Orders
database. In Figure 19-5, sequence # 3 from System to OrdersDB is a synchronous message
because the System will wait for the answer to the find request. The return in sequence #4
is an Order object, the same Order object that you put on the diagram at the start.
:OrderFullfillment Clerk
:OrdersDB
4 : return 12345678
1 : getOrderNbr():int
3 : getOrder(ordernbr.int) : Order
2 : return 12345678
:System
Figure 19-5
Modeling the second step in the flowchart: Find the Order