Partial TO in LB10

Gurus,

I am doing material staging for production order with PP-WM interface.In CO01 i generate the pull list.

When goto LB10 & try to convert the TR into TO if there is 10 BOM material & if there is shortage

for even one single material it is NOT allowing to convert the TR into TO.It gives an error stating unable to find source

storage bin,So how to come overcome this issue  & create Partial TO for partial qty available since i am not able  to delete the

shortage qty in TR..

I have done the setting in OPKP as complete transfer requirement & confirmed qty for TR as UNTICKED.

I am working with pick parts..