How LN's Tools 4GL, VRC code-layering, DAL/DAL2 hooks, and business object scripts map to D365's X++ metadata model, extension-first architecture, chain of command, security, and Azure DevOps ALM. Includes a direct account of the cultural change teams must anticipate.
What you will be able to do
Describe LN Tools's 4GL, data dictionary, session architecture, and domain model
Explain VRC (Version–Release–Customer) as a code-layering mechanism
Describe DAL and DAL2 and their role in LN business logic extensibility
Explain D365's extension-first model and why standard source modification is forbidden
Map LN customisation patterns to D365 equivalents (extensions, event handlers, chain of command)
Describe the ALM toolchain change from LN's VRC version control to D365's Azure DevOps deployable packages
Introduction
LN and D365 are both mature ERP platforms, but the experience of extending and customising them is profoundly different. LN's Tools 4GL gives developers a single environment where they can read, modify, and check back in any part of the system — including Infor standard code — under VRC version control.
LN Tools: the 4GL, sessions, and the data dictionary
LN's development environment is Infor Tools (historically called Baan Tools). Tools is a proprietary 4GL environment consisting of:
VRC: the three-layer code architecture
When a developer checks out a session from the VRC repository and modifies it at the Customer layer, the modification is stored as a delta against the Release or Version layer. The build system merges the layers to produce the deployed binary.
DAL, DAL2, and business object scripts
DAL (Data Access Layer) is LN's abstraction for database operations. DAL scripts intercept database events: pre-insert, pre-update, pre-delete, and post-equivalents. A Customer-layer DAL script can add validation before a record is inserted, or populate a field after a record is updated.
The D365 extension model in practice
A D365 extension package is a separate Visual Studio project in Azure DevOps that references the standard D365 model by name. It contains only additive objects:
Security: roles, duties, and privileges
LN security is session-centric: access is granted to specific sessions, and within a session, to specific options (create, view, update, delete). Segregation of duties is enforced by granting or denying session access.
Knowledge check
Summary
The LN-to-D365 development migration is a re-implementation, not a conversion. The architectural difference — edit-in-place VRC versus additive extension packages — is the single most important thing for LN development teams to internalise before the build starts.