Workflow Does Not Execute In Subform

Workflow Does Not Execute In Subform

Hi all,

 I have a form workflow that is working as a stateless form, but when I use the form as sub-form the workflows does not work. 

 I have added a workflow in the form, but the workflows only works on the first row, but not the additional row I add in.

My Scripts:
//
temp = Size[ID == input.Grading.Size];
input.Grading.cbft= (temp.HxW * input.Grading.length * input.Grading.pcs) / 144;
input.Grading.Tonnage = input.Grading.cbft / 50;
//

Any pointer or help will be highly appreciated.