Patterns: Building Serial and Parallel Processes for IBM WebSphere Process Server V6

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.

Actors

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

Status Primary

Relationships

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

Wholesalers

Table 8-8 provides details about the Place Order with Multiple Wholesalers use

case.

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

wholesale systems

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

system.

Notes

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

link business

processes across separate enterprises

applies.

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.

Place Order

Place Order

Retail System

Retail System

Wholesale System A

External Wholesale System C

External Wholesale System D

External Wholesale System E