Patterns: Broker Interactions for Intra- and Inter-enterprise

Chapter 3. Application Integration pattern 35

3.2 Defining the Application Integration patterns

This section defines the Application Integration patterns by documenting the

Business and IT drivers that lead to the selection of this pattern, the context

within which it can be used, the proposed solution, and examples of its usage.

It also discusses typically observed application integration requirements that

can help determine which of the two Application Integration categories

(Process-focused or Data-focused) you should use in designing your e-business

solution.

3.2.1 Business and IT drivers

Typical Business and IT drivers that result in the selection of this Integration

pattern are:

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

and information.

򐂰 The business activity needs to aggregate, organize and present information

from various sources within the organization.

3.2.2 Context

Application Integration patterns can be observed in solutions that call for close

integration with systems and databases that exist within the organization. It

serves as a back-end integration pattern, and is critical for the successful

implementation of certain Business patterns. For example, solutions that use the

Self-Service business pattern or Extended Enterprise business pattern often rely

on these same application integration techniques. Similarly, many Custom

designs and Composite patterns use Application Integration application patterns.

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

wholesale departments. Currently, both departments have proven IT

infrastructures but have no inter connectivity. The Process-focused Application

Integration patterns address this problem. These patterns can be applied in a

case where the business process needs to be integrated between existing

business systems within the organization. The Process-focused Application

Integration patterns can be used to integrate the retail ordering and wholesale

inventory systems, eliminating ordering lag and providing an up-to-date

inventory.

3.2.3 Solution

The Application Integration pattern typically consists of the following elements:

36 Broker Interactions for Intra- and Inter-enterprise

򐂰 Business applications and data that need to communicate, interact, and

integrate with other business applications and data within the organization

򐂰 A network which:

– Is based on TCP/IP and other Internet technologies, or on proprietary

protocols

– Can be a dedicated LAN or WAN connection

򐂰 Other business applications and data which can be:

– Custom developed systems (old and new)

– Enterprise Resource Planning systems and other packaged applications,

such as SAP, BAAN and PeopleSoft

– Databases

򐂰 Application integration services, which include:

– Protocol Adapters

– Message handlers

– Data transformation

– Decomposition/recomposition

– Routing/navigation

– State management

– Security

3.2.4 Putting the pattern to use

This is probably one of the most commonly used patterns and it can be observed

in any solution where an application needs to integrate with other applications,

legacy systems and databases. Examples include:

򐂰 An electronics retailer/wholesaler, ITSO Electronics from our sample

scenario, needs to integrate their retail ordering process with their inventory

management system.

򐂰 A telecommunications company needs to integrate their online sales systems

and their core provisioning systems to improve efficiency and customer

service.

3.2.5 Application Integration considerations

Choosing the right Application Integration pattern can only be done in the context

of specific solution requirements. These requirements encompass not only the

specific needs of application integration to be deployed, but also the constraints

posed by the enterprise's existing IT infrastructure and technology investments.

This section details considerations to be made and questions to ask in

determining the best integration technique for a solution under consideration.