Extended Enterprise general guidelines

To help you determine if the Extended Enterprise business pattern is appropriate for the design of your Web-based application, the following information details the business and IT scenario into which an Extended Enterprise solution fits.

Business and IT Drivers
Businesses developing a solution needing the following characteristics should consider using the Extended Enterprise business pattern:

• The business process needs to be integrated with existing business systems and information.
• The business processes need to integrate with processes and information that exist at partner organizations.

Context
Consider an online travel agency that enables customers to make travel arrangements. Customers can choose from a wide variety of accommodation options including resorts, hotel chains, and small bed and breakfast establishments. The travel agency requires that all participating major business partners such as resorts and hotel chains provide programmatic interfaces that can be invoked in real-time for checking room availability and making reservations. This is a classic example of business-to-business programmatic integration. Conversely, small bed and breakfast establishments usually cannot afford to provide such programmatic interfaces to their reservation systems. To accommodate such small business partners, travel agents’ web sites provide a user interface that can be accessed by the operators of the bed and breakfast for manually entering room availability into the system. Such user interface based interactions between partners are not covered under this pattern. Instead they can be modelled using the Self-Service business pattern discussed elsewhere on this Web site.

The general problem addressed by this pattern is illustrated in the following figure. Interactions between partners form a public process, or potentially multiple distinct public processes. Each of these must be integrated into the private business process flows implemented by each partner. Such integration might be as simple as passing data to a particular application, or as sophisticated as initiating or resuming a multi-step workflow involving several applications and user interactions. For example, Partner A and Partner B agree upon sharing specific business processes and a process flow. Partner A invokes a public process flow that in turn may invoke a specific 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 it expects in response to the invoked public process. The golden rule of business to business integration is the less you know about the business partner’s private processes and the implementation details of their applications the better off you are. This allows for loose coupling between partner applications. Such loose coupling enables organizations to evolve their applications without affecting business 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.

Solution
The Extended Enterprise pattern might consist of all or some of the following elements:

• Business Entities, which typically:
  • are programs, applications or databases that exist within an organization
  • access and connect to other Business entities across the network
• A Network which:
  • is based on TCP/IP and other Internet technologies
  • can be a dedicated Wide Area Network (WAN) connection
• Business Rules that:
  • manage the integration between the Business entities
  • describe Trading Partner Agreements
  • use Workflow rules to determine the sequence of steps and the data flow that needs to be used to facilitate the integration. These rules:
    • describe the sequence of steps that a message needs to go through before being transferred to the other business entity and
    • specify how and where the message should be delivered
  • use Transformation Rules to specify format and protocol transformations that need to be applied to messages that flow between the business entities
• A set of interactions that include:
  • the execution of a jointly-agreed business process

Putting the Pattern to Use
This pattern can be observed in solutions such as:

• Business-to-Business procurement sites that implement a series of workflows to facilitate the electronic procurement of goods and services.
• Extended Value Chain functions within e-Marketplaces that support cross-enterprise processes such as demand planning and collaborative design.

What's Next
If you have determined that the Extended Enterprise business pattern can provide an appropriate solution design for the application you are developing, next select an Application pattern.

If the Extended Enterprise business pattern is not appropriate for your development efforts, review the Business patterns to determine which pattern best addresses your e-business needs.