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2.
Extends
Extend is a type of relationships between use-case
with its extension(s). Use-case extension itself is a
use-case consists of detailed steps extracted from
the more complex original use-case for
simplification. Extension use-case widens the
functionality of the original use case.
As shown in Figure 2.6, the original use case (Place
New Member Order) is having two extension use
case which are Generate Warehourse Packing and
Calculate Order Subtotal & Sales Tax. These two
extension use case is a more detailed steps which
explained the original use case.
Figure 2.6 Extend relationship
<<extends>
<<extends>>
Generate Warehouse
Packing Orders
Place New
Member Order
Calculate Order
Subtotal & Sales Tax
 |