Mass uploading of PIR

Hi friends,

We have tried to mass upload PIRs freight condition to modify the price of one particular vendor PIRs by using the customized T code . When we uploaded it all, the prices was not changed. Therefore, we tried to separately upload per plant. When we upload PIRs for plant X, all records were updated correctly. But when we upload again for Plant Y, it uploaded correctly for Y. But the Value for the X, was changed as same as the value of Y. The problem encountered was that the tool was not considering the plants for change and only the PIRs. Thus, it modifies time again to the records of the last update.

Can any one help me what will be the cause of this

Even Small lights will be highly appreciated

Thanks in advance

Manickss