You can always put the RandomNumberGenerator in a custom transformer and configure it to do group by.

Added workspace demonstrating this.

@nielsgerrits​ 

Thanks for your help,

I am no getting the same option as your workspace when I right client on random transformer to convert to custom transformer

That is correct, by default there are no Parameters for a Custom Transformer. You have to configure this yourself:

• Open the contents of the Custom Transformer.
• In the Navigator, go to Transformer Parameters.
• Right click on "Group by" and choose "Create User Parameter".
• Click OK in the "Add/Edit User Parameter" window.

This can also be done for Transformer Parameters in the Custom Transformer:

• Open the Transformers Parameters.
• Click on the down arrow right of the field or setting.
• Go to "User Parameter..." and choose "Create User Parameter..."
• Click OK in the "Add/Edit User Parameter" window.

These paramaters are now added to the custom transformer.

@nielsgerrits

thanks so much working