Object Relationship Service 
The object relationship service offers you the possibility to also relate documents with similar contents over application and system boundaries. Thus, navigation between the different documents in a business process is possible.
Example
In a business process in sales, a request for a quotation is followed by a quotation, then an order and then a delivery occurs. The person responsible can trace the business process directly from the delivery by using the documents.
You can relate objects using multiple steps and create whole relationship networks. Access to the relationship records is possible from every object involved. You can call these functions using the interface, without the need to implement a separate application logic. The relationship service provides a browser for the end user.
The relationships can also be created with documents from various SAP Systems and non-SAP Systems. Navigation to the objects outside an SAP System is also possible.
The object relationship service is a component of the SAP Web Application Server that transfers creation, reading and changing of relationships. The relationships are modeled by application developers and are transferred to the object service using an interface.
Note
The object relationship service has been reimplemented for SAP Web Application Server release 6.10. In comparison to the predecessor, the new service offers the possibility to relate persistent objects (business classes) in addition to business objects. Objects can also be related, without the need for the roles to be persistently saved. You can find documentation related to maintaining and migrating older object relationships in the section Object Relationship Service to Release 4.6D.
Application developers who have used the relationships for an earlier release can continue to use the predecessor. However, the new object relationship service also provides tools for migration. If you want to model new object relationships in your application, SAP recommends that you use the new service.
Application developers can find more information in Connecting to the Object Relationship Service.
The object relationship framework provides the following functions:
Maintenance of role-based relationship models
Logging of those responsible for the relationship and last changers
Creation, change and deletion of binary relationships
Connection to the update using the persistence and transaction services of object services
Support for cross-system relationships
Support for application attributes to relationship records
Reads the relationships of an object
Existence check of relationships
Archive connection
Tools for the transfer of model data from the old relationship service
In comparison to its predecessor, the new object relationship service offers new functions in the following areas:
Model data maintenance:
Logging of the last changer of a relationship or role
Logging of a responsible developer for a relationship or role
Warnings if roles are used again or if incompatible changes are made to the model data
Checks on the validity of database tables and object types
Application attributes:
More flexible table structure
Key: Relationship GUID, attribute name
No restriction to 250 CHAR for application part
Access to attributes possible using View
Support when creating, deleting and changing attributes