Integration of legacy systems into a modern enterprise SOA (part 5 + 6)

Integration of legacy systems into a modern enterprise SOA - Part 5 and 6


5. Impact of SOA on the legacy system

If servce-oriented rules are applied while integration, the level of reusability of the components of the legacy system can be increased. By using loose coupling, both the business process and the use of the integrated component will be more flexible. Changes in processes are now even easier to implement. The complexity level of the complete system will be reduced by use of standard (integration-) components. This can also be relevant for monitoring and maintenance.


6. Ways of integration

Application integration

One of the main tasks that must be achieved is the integration of business logic, the mapping of rules and workflows. In many cases it is not sufficient to wrap existing logic publish it as a webservice. Maybe batch processes have to be transformed into a callable function. Transformation- and mapping logic must be added to the interface. Parts of the previous business process could be changed. Furthermore, transaction security must be observed and guaranteed.

Data integration

Relational and not relational data must be published on the interface. Dependant on the legacy system, an existing persistence layer must be used or even a new layer must be created. Here also transformations must be conducted at the interface to present data in a general valid format. Maybe a canonical data model should be taken into consideration.

presentation (view) integration

If access to data and application logic is not practical due to different reasons, as an alternative one can integrate the legacy system directly on the presentation layer. The aim is here to replace all terminals, which access the mainframe. The different forms, screens and menues must tapped/scanned at the mainframe and be made available as a service, e.g. in a modern JEE application. It is advisalbe to integrate the forms and menues of the legacy systems into a portal or a modern application by which they are presented to the user.

Part 7 will follow next week...