This glossary defines key terms used throughout the Planner documentation and platform. These concepts are foundational to understanding how modernization planning, execution, and governance work in Planner.

Action (Modernization Action)

A modernization operation applied to a legacy asset (e.g., application, data store, gateway). Actions include Refactor, Rehost, Reimagine, Augment, Capture, and Extract. Each action produces a defined change in architecture or runtime.

App

A logical representation of a functional software unit. Apps can exist on the legacy or modern side. For example, card_mng might be a CICS app, while card_mng-service is its modern service counterpart.

Baseline

The current state of the legacy and hybrid landscape. It includes discovered applications, gateways, data sources, and their dependencies. The Baseline is the foundation for any modernization plan.

Bridge

An OpenLegacy runtime component that exposes modern APIs (REST/gRPC) to legacy or decoupled systems. Bridges are auto-generated by Planner to connect legacy calls to modern implementations.

Capture (CDC)

A Plan Action that sets up Change Data Capture from legacy data sources (e.g., DB400). Capture emits change events without modifying the legacy application logic.

Decoupling

A design pattern that allows legacy systems to call or be called without tight coupling to modern services. Includes Internal Decoupling (inside legacy platform) and External Decoupling (via gateways like CTG, IMS, MQ).

Environment

A technical execution context, such as "Mainframe," "Kubernetes," or "Cloud." Environments define where applications run and how they are deployed.

Gateway

An integration entry point into legacy systems, such as CTG (CICS), IMS Connect, or MQ. Planner uses gateways to model how external or internal systems communicate with legacy components.

Hub

OpenLegacy’s orchestration and governance layer. Planner integrates with Hub to track, execute, and monitor modernization plans.

Interceptor

A component that intercepts gateway calls (e.g., CTG or IMS) and routes them to a modern service without changing the original consumers. Generated and deployed via Planner.

Link

A relationship between two assets in the model — for example, an app calling another app, an app using a database, or a gateway connecting to an app. Links form the dependency graph in the Baseline and Plan.

Plan

A governed sequence of modernization actions derived from the Baseline. The Plan includes actions, their dependencies, execution steps, generated components, and task tracking.

Project

A unit of generated or managed code associated with a specific modernization action, typically involving OpenLegacy services, Bridges, or Interceptors. Projects are part of Plan execution.

Proxy

An internal pattern used in Internal Decoupling. The proxy enables legacy code to call a modern service as if it were a legacy call.

Service (Modern Service)

A cloud-native or containerized application that implements business logic previously handled by legacy apps. Services are the modernization target for many actions.

Task

A step in the modernization Plan — such as creating a project, configuring a gateway, deploying a Bridge, or executing a test. Tasks are governed by Hub and traceable.

Zone

A grouping mechanism for logical or physical systems. Zones help separate concerns across platforms — such as "Mainframe", "Cloud", "Digital", or "Integration" — and influence how visibility and links are scoped.

🧭 See Also