VT02N - do PGI and Invoice for certain deliveries either based on certain conditions

Hi Friends ,

We are using VT04 for creating shipments . While shipment completion stage in VT02N   an activity profile has been maintained  which does both the Goods issue and Invoice.

We have a business requirement , PGI and Invoice should be created only for specific set of deliveries based on certain conditions.

Is there any standard way to do this or by using user exits.

Please guide.

Thanks,

Nileshsa.