Design Guidelines for Cost-Efficient Upgrades
A Microsoft Dynamics AX application is typically upgraded a number of times during its lifetime. Upgrades may be made to the standard application, or to customized parts of the application. If the application is not designed according to some fundamental principles, upgrading can be expensive and very time consuming.
This section of the SDK describes the relative cost of changing different types of application objects, and describes which layers should be modified in different circumstances.
Also refer to Designing a Microsoft Dynamics AX Application.
For information about the upgrade process, refer to the Microsoft Dynamics AX Implementation Guide.