This activity is used to add a new modification reference to an active modification. When you add a modification reference a due calculation is triggered for the referencing modification. This due calculation will automatically update the list of pending maintenance events.
When the modification revision is in the Preliminary status, you can add modification references in the Modification Details/References tab. However, once the modification revision is activated, you can only add or remove references by clicking Add Reference or Remove Reference in the tab. The following table shows the valid modification reference types:
| Reference Type | Description |
| Mandatory | This indicates that the referenced modification revision must be complied with before this modification can be complied with. Furthermore, if this reference type exists for several modifications, these modifications need to be complied with first. The Reference Compliant field (in the Modification Details/Assign Serials tab) will indicate whether all Mandatory and Exclude modifications are complied with or not complied with. |
| Info | References of this type are for informational purposes only and affects nothing else in the system. |
| Exclude | Excludes the compliance of this modification for all serials that have complied with the referenced modification revision. The Reference Compliant field will indicate whether all Mandatory and Exclude modifications are complied with or not complied with. |
| Supersede | Indicates that this modification revision supersedes the referenced modification revision. When setting this modification revision to the Active status, the referenced modification revision will automatically be set to Obsolete. A reference of type Superseded By will automatically be inserted into the Referenced Modification Revision field. The initial value for the Perform Modification field (in the Modification Details/Assign Serials tab) will be decided upon based on the Modification Category and the Supersede Rule in the Define Modification page. |
| Superseded By | Indicates that this revision was superseded by the referenced modification revision. It is not possible to manually create records with this reference type. Superseded By records are created automatically when the superseding modification revision is set to the Active status. |