updating standard lot size on items does not update lot size in costing

We are on 12.1.3 .When we update the standard lot size under teh costing tab in the items screen for a certain item , we have noticed it does not automtically update the lot size in the costing screen for that item.The lot size on the costing screen has to be updated manually to the value in the items screen .Is there way to have that done automatically whenever teh standard lot size on the items screen is updated?

thanks

rahul