AS400/RPG to Java API migration

[MatthiasVDE]

In our company we have a monolithic as400 system with a DB2 database. The long term plan is to migrate everything to a new service oriented Java API platform.

The architectural plan is to expose the necessary RPG Routines as SOAP Web Services (1 on 1), and then transform them to REST services with the help of IBM Integration Bus. The REST services must already be based on the new data model. On top of the IIB layer we will create a Java API layer (with API Connect above) to provide data to the consumer applications. In fact, we will do SOA/API.

The problem is that the whole project approach is bottom-up, we do not have any contact with the business, only with the AS400 analyst/developers (dinosaurs  .

One of the steps in the whole plan is to create use cases, use cases that will be used to create the granularity for the API's. So, my question is, what is the best approach to create use cases, bottom up, from AS400 RPG routines?

[qwerty]

RPG (Rate Probiere Gucke). Since you asked, I would recommend what I wrote in my BA book. I once wrote that based on a RE process for another dinosaur system.

q.