SSIS access permissions are managed via Component Services. It is the DCOM object named MSDTSServer. Here are the steps to follow.
- Component Services -> Computers -> My Computer -> DCOM Config -> MSDTSServer
- Right click on MSDTSServer
- Click properties
- Click on the Security tab
- Select Customize and add the users/groups to the Launch/Activation and Access tabs accordingly
- Add the user to the local Distributed COM Users group
- Restart the SSIS service