Integration of legacy systems into a modern enterprise SOA (part 7.1)

Integration of legacy systems into a modern enterprise SOA - Part 7.1

7. Approach

1. Pre- and analysis phase

In a first phase the legacy application which should be integrated und the calling business process should be analysed thoroughly. With standard application the level of customer-specific changes in the application must be identified (customizing quote). Documentation and calling methods of these changes must be checked. If the customizing quote is high, it must be decided, if the use of standard adapter is still reasonable. Often, with individual customer-specific legacy systems the only way of integration is using the application data layer. It must be checked how data persistence was implemented.

The state of documentation is also very important regarding the application which should be integrated.

- do process maps and system manuals exist?
- is there documentation of data models / object models?
- are there application-specific interfaces (APIs), which can be used?
- how does the legacy system act regarding security?
- how do the components communicate between one another?
- with multi-tier architecture, are there reusable components, applications server, data dictionaries, etc. ?
- are there possible interests and issues of the operating department?


2. Planning phase

The planning phase follows the analysis phase. If needed, a new modelling of the target processes is conducted in the planning phase. This is based on the process documentation which is created in phase 1 (actual process). At that time it must be clarified how the target architecure should be composed.

During the planning phase the following topics have to handled:

- which topology will be introduced? (e.g. bus topology)
- is the use of a canonical data model reasonable and effective?
- do any standard application packages exist ("packaged integration solutions", e.g. Oracle AIA)
- do any reference archtecture exist?
- how can the user experience of the new process be improved?
- ...

Part 7.2 will follow next week...