You need to set up permissions for the different users at runtime.
You have opened the testing tool. To do this, go to: http://<host>:<port>/caf → Test Tools → Authorization Assignment.
...
1. Navigate to demo.sap.com → tutorial → modeled.Student
2. Choose New Rule and enter StudentRule.
3. In the Principal Name field, enter the name of the user to whom you want to give access to business object Student.
4. Choose Add Selected to ACL.
If the name you have entered has multiple matches, a dialog box displays all the options. Select one and choose OK.
5. From the Permissions dropdown box, select fullcontrol.
6. Choose Save Business Rules.
You can test now the permission checks again. This time the test should be successful: