Patterns: Extended Enterprise SOA and Web Services

Chapter 4. Extended Enterprise pattern 65

guidelines in the next section provide additional information about choosing this

business pattern. Business and IT drivers, the e-business context appropriate for

this solution type, and additional solution details are discussed here.

If you determine that the Extended Enterprise business pattern can provide an

appropriate solution design for your business needs, the next step is to select an

Application pattern. The Extended Enterprise business pattern can be

implemented using any one of three Application patterns discussed here. They

provide solution flexibility so that the selected Business pattern can address the

specific needs of the business process being automated.

4.2 General guidelines

This section details a business and IT scenario for an Extended Enterprise

solution and helps you to determine whether the Extended Enterprise business

pattern is appropriate for your interenterprise application integration.

4.2.1 Business and IT drivers

Use the Extended Enterprise business pattern if your business is developing a

solution with the following characteristics:

򐂰 The business processes need to be integrated with existing business systems

and information.

򐂰 The business processes need to integrate with processes and information

that exist at partner organizations.

4.2.2 Context

Figure 4-1 on page 66 illustrates the general problem addressed by this pattern.

Interactions between partners form a public process, or potentially multiple public

processes. Each of these processes must be integrated into the private business

process flows of each partner. Such integration can be as simple as passing data

to a particular application, or as sophisticated as initiating or resuming a

multistep workflow involving several applications and user interactions.

For example, Partner A, the source application, and Partner B, the target

application, agree upon sharing specific business processes and a process flow.

Partner A invokes a public process flow that, in turn, invokes a private, internal

process flow within Partner B’s organization. Partner A is not concerned with the

details of Partner B’s private process flow. Instead, Partner A cares only about

the results that it expects in response to the invoked process in Partner B.

66 Patterns: Extended Enterprise SOA and Web Services

Figure 4-1 Extended Enterprise context

The golden rule of business-to-business integration is that it is better to know

less about the trading partner's private processes and the implementation details

of their applications. This loose coupling enables organizations to evolve their

applications without affecting trading partner's applications.

Obviously, specific functionality supported by these applications depends on the

particular details of the trading partner agreements and service level agreements

between the organizations involved. Yet a survey of such applications in multiple

industries reveals certain common approaches that have been successful. These

commonalities of success are harvested as the various Application patterns that

can be used to implement this Business pattern.

For example, consider the case of a company that wants to integrate their retail

organization with a range of external manufacturers. The Extended Enterprise

pattern improves organizational efficiency and reduces the latency of business

events by integrating the external manufacturers with the inventory

replenishment system and reducing the likelihood of unfilled orders. The

Extended Enterprise pattern also applies a structured exchange with trading

partners and supports real-time access to and from applications. This allows the

resellers to receive the benefits of an updated inventory and receive real-time

notice of any out of stock items.

The Extended Enterprise pattern also allows this company to minimize

application complexity and to integrate their applications with resellers that have

unique infrastructure designs. They can leverage their current skills and existing

investments, while eliminating the need for extensive retraining and infrastructure

investments.

Nonshared

business

processes

Nonshared

business

processes

Nonshared

business

processes

Nonshared

Process

flow

Nonshared

business

processes

Nonshared

business

processes

Nonshared

business

processes

Partner A

Nonshared

Process

flow

Nonshared

business

processes

Nonshared

business

processes

Shared

business

processes

Shared

Process

flow

Partner B