Jamal,
I have tested macro manually from macro workbench, it ran successfully. But when it works from process chain its getting failed.
Open the planning book that is used by the Process chain. Select records using the exact same selection used by the Process chain. Now, run the macro manually. If it executes without error, then you have a problem in your process chain.
....but its not possible to check all the product master data because of too many products are exist then i checked some products randomly everywhere conversion of UOM has maintained.
Don't be silly, of course you can check them all. U/M data is stored in table /SAPAPO/MARM.
Best Regards,
DB49