ri!parts is an intenger (it's your parameter), but local!parts, as you can see in the local variables section is a complex type... tha's why it's failing...

Thanks for the reply David,

Then what can be done, what change makes this code work, please let me know, so that i can change it and test.

Thanks in advance.

Try to save same types in your expression (Number- Number or complext / complex)

What do you want to save?

I want to save the vehicle details

IN that case, the value of the input parameter must be of the same type as the recordType you are trying to save...

Sorry for making it lengthy conversation

Below is the relationship between two record types

Expression rule for the same, 

Rule Input field

Sharing these, I saved them as Integer data type or my understanding wrong from your question , please let me know

Don't worry.... The problem is here...... both have to be of the same type.

Don't worry.... The problem is here...... both have to be of the same type.