After investigating, I found there are some data existing on 7.5.1 (Plan) and it will effect to 7.5.5. Because 7.5.5 will select data 7.5.1 (Plan) and 7.5.2 (Firm) to create schedule type 3 (Required Ship Update).
To prevent the error: Duplicate data , we need to do as following steps:
1- Delete data on 7.5.1 Customer plan schedule Maintenance
2- Delete data on 7.5.2 Customer ship schedule Maintenance
3- Delete data on 7.5.3 Required ship schedule Maintenance
4- Rerun 7.5.5 Required ship schedule update
To solve this problem , I will explain to you again ka.
Please let me know - when you have available time ?