124 Patterns: Building Serial and Parallel Processes for IBM WebSphere Process Server V6
8.2.3 Scenario 3: Ordering on demand with multiple wholesalers
After the successful implementation of scenarios one and two, the increase in
revenue has resulted in monetary rewards for employees in the ITSO Electronics
IT department. While the staff is celebrating, change continues rapidly. Also
ITSO Electronics’s two wholesaler departments have just merged, with
Wholesaler B migrating all its processes to Wholesaler A’s systems. With this
change, the business managers have become concerned that a single
wholesaler may not be able to supply every product in a timely manner.
This could lead to frustrated customers and cancelled orders. Traditionally, ITSO
Electronics has maintained relationships with a number of external wholesalers.
The next challenge is to incorporate those wholesalers into the order process.
The new process includes a rule that if the internal wholesaler cannot deliver a
product in a “timely” manner, third parties are given the opportunity to do so.
Furthermore, the definition of
timely is expected to change with business
conditions, so the rule describing timeliness must be changeable by a business
analyst without requiring IT department intervention. Finally, since business
partners can and will change regularly, the process must accommodate the
available partners when it is executed.
For scenario 3, we identify an additional actor, External wholesaler. We can also
identify an additional
use case, Place Order with Internal or External Wholesalers.
Table 8-7 provides details about the external wholesaler.
Table 8-7 External wholesaler actor details
Actor name External wholesaler
Brief description An ITSO Electronics business partner who can supply
wholesale products and has agreed to participate in
ITSO Electronics’s order process
Associations to use cases 003 Place Order with Internal or External Wholesalers
Chapter 8. Business scenarios used in this book 125
Use case 003: Place Order with Internal or External
Table 8-8 provides details about the Place Order with Multiple Wholesalers use
Table 8-8 Use case 003: Place order with internal or external wholesalers
Use case name 003 Place Order with Internal or External Wholesalers
Subject area Wholesale ordering
Business event An item sold by the retail division needs to be fulfilled from
either internal or external wholesale inventory. If the internal
wholesaler cannot fulfill an order in a timely manner, the
order is forwarded to external wholesalers.
Actors Retail system, internal wholesale systems, external
Use case overview The retail system places an order for an item with the
internal wholesale systems. If they cannot fulfill the order,
the process queries external wholesalers until it finds one
that is capable of fulfilling it.
Preconditions The retail system supplies a part number and the quantity
to be ordered.
Termination outcome 1 The retail inventory system records the confirmation
number of the order, the wholesale system where the order
was placed, and the expected delivery date. If no
wholesaler can fulfill the order, the process notifies the retail
126 Patterns: Building Serial and Parallel Processes for IBM WebSphere Process Server V6
Figure 8-8 illustrates the use-case model of scenario 3.
Figure 8-8 Scenario 3 use-case model
Selecting an Application pattern
Table 4-3 on page 65 and Table 4-4 on page 66 list the business and IT drivers
for selecting the Extended Enterprise::Exposed Serial Process application
pattern. In addition to the drivers listed in scenario 1, the driver to
processes across separate enterprises
Since there are no longer two internal wholesalers, the IT department decides to
revert to an Exposed Serial Process as they assess the effects of opening up the
process to third parties. To fulfill the flexibility requirements, they design a
business state machine to query all available partners until one fulfills their
request. Since external partners cannot be trusted in the same way as internal
ones, they design the business state machine to properly handle cancellation by
a partner. Partner interactions are secured with WS-Security as well.
Wholesale System A
External Wholesale System C
External Wholesale System D
External Wholesale System E