Indirect Export where Goods altered/additions made during export process

In case of indirect export, the goods should be exported in the same condition as being purchased exception minor alteration. But where in case when overseas customers purchased goods like heavy machineries/commerial trucks etc and do addtional modification/alteration from an other local suppliers to make it as per thier requirement & use and then export.

In this case, it is 0% sales for supplier or need to apply 5% as the goods are not exporting in the same condition as sold and such locally value addition may be upto 50% of value of the sold goods.