I have to purchase mat M1 from vendor V1 to whom I have given mat M2 which is assembled with M1. I supplied M2 to V1 directly after purchasing M2 from V2.
Shall I use subcontracting scenario or something else.
You can use Subcontracting scenario for this.
While creating Purchase order you need to create the two line items as below,
1. One line item with subcontracting charges and in the component list Material M1, with item category L.
2. Another line item for procuring material M2.
With this your both e purpose will get solved of paying vendor charges for assembling & procuring materila M2.