In case of a price deviation between the supplier order/confirmation (SPO/SOA) and supplier invoice, user will receive a message on the invoice item (SIN item)  regarding the price deviation. 

On the invoice item (SIN item) user will have an F12 option called "Accept warning ST = 3". 
This will accept the "warning" and forward the invoice item (SIN item) to ST=3. 
Once you have registered supplier shipping advice (SSA) to ST = 3, the job will link supplier shipping advise to the supplier invoice (SIN). 

A rule can be activated that will automatically change the price on the SSA-item. 
User decides the amount of price deviations to be accepted in % and in amounts. 

For example, the price deviation may be up to 10% but max 150kr between SSA.PRICE and SIN. PRICE for SSA. PRICE to be updated. 
The SSA. PRICE will be automatically updated by the job that links SSA and SIN. 

User can update the price manually using the F12 options on the SSA if no automation is needed.