This page describes the transition plan from current (2018) OpenIMIS implementations to the targeted (modular architecture) described in Target (modular) Architecture

The transformation from current architecture to the modular architecture will be iterative and incremental.

Iterative

At the end of each iteration, a production-ready version of OpenIMIS will be delivered.

To be production-ready implies that, at each iteration:

• a migration of (re)implemented features is prepared  (with dry run,...)
• tests (integration , load and acceptance) are formally organised
• documentations (from user guides to deployment procedures) are delivered

Each project will have the choice to join the new OpenIMIS platform at that iteration or not.

Incremental

The aim is to cover all current OpenIMIS features (of each implementation) with plugins in the (new) OpenIMIS.

However, not everything will be ready at first iteration. To ensure a production-ready delivery, OpenIMIS will, as a consequence, be built upon proxy plugins to (legacy) implementation.

Proxy plugins will be developed in the various layers and will be replaced once the new implementation is ready.

The very first iteration of OpenIMIS will thus be a "all proxy" implementation where every (functional) feature is a proxy in the (web) frontend layer to existing OpenIMIS implementation:

Next iterations will be planned to replace chosen proxy(ies) to their target implementation.

The core components (FE, BE,...) of OpenIMIS will be built (enhanced) along the proxy replacements.

The choice (order of) proxy replacement will thus be based on:

• what is needed from the core components, and its availability
• what has the most value (business wise)

Example, should we identify the Payers-related features as interesting to migrate first.

An iteration may target the Payers FE proxy replacement by implementing a BE proxy, targeting current OpenIMIS API (WebServices):

Depending on the identified workload, the iteration may even skip the BE proxy and connect the actual Payers BE plugins (Online and Batch) implementation: