# Change Handler Helpers for Maintenance Objects

The Business Object based Maintenance objects have some standard validations. The Helper classes described below will help in reusing the validation code. The Change Handler Helpers have been created for the following objects:

- BO based MO.
- Standard MO Log table.
- Standard MO Log Parameter table.

- BO-Based MO
- Standard MO Log Table
- Standard MO Log Parameter Table
- Additional Validations

Parent topic: Developing Change Handlers