Migrate or rewrite legacy RPG applications

Projects for migrating or rewriting legacy AS/400, iSeries and IBM i applications typically following these high level activities:

  • Understand the existing application
    • Data model
    • Business rules
    • Design recovery
  • Design and develop the new application
    • Redesign or create new designs
    • Generate code automatically where possible
    • Manually code where necessary
    • Compare original application with new application

Critical to all of this, of course, is expert and experienced project management – vision and leadership.  Click here to learn about how vLegaci can help with designing and leading your project.

Databorough offers a comprehensive, state of the art suite of tools for facilitating all steps of migration and rewite projects on the AS/400, iSeries and IBM i.  Here is a quick overview:

Data Model – Understanding the existing data model is facilitated by the Data Model Extraction module which provides a number of views, one of which is the ability to focus on parent-child relationships for a given table:

AS/400 iSeries IBM i data model diagram
Business Rules – Typical ERP applications have thousands, tens of thousands or even hundreds of thousands of business rules.  When developing or migrating systems these rules must be dealt with completely and accurately.  A good starting point is to use the Databorough Business Logic Extraction Module to extract the business rules via the process depicted and produce an inventory of business rules as shown below.

AS/400 iSeries IBM i business rules extraction process

An example of a list of extracted business rules – this can be drilled into.

AS/400 iSeries IBM i business rules extraction inventory catalog

Design Recovery, Reengineering and Rebuilding – The Databorough Application Reengineering Module and Design Recovery and Rebuild Modules automate and assist most of the process of migrating or rewriting AS/400, iSeries and IBM i applications.

The Application Reengineering Module provides a number of alternatives for reengineering the database and database access:
AS/400 iSeries IBM i database reengineering
The Design Recovery and Rebuild Module pulls together the previously extracted data model, business rules and UI model to create a set of components and design documents necessary rewrite or migrate a legacy AS/400, iSeries or IBM i application.

Following the MVC architecture pattern various components are generated automatically or with assistance, as needed.  View layer components are generated using JSF/Facelets.  Controllet layer components are comprised of Java Beans, and in the future RPG modules.  These components may also be presented as Web Services for a Service Oriented Architecture (SOA) solution.  The model layer is presented as, optionally, Java, Stored Procedures or RPG.
AS/400 iSeries IBM i application reengineering
For further information about these modules, or about how to construct a successful reengineering project contact vLegaci.