This is one of the loss calculations that Navarik automatically performs to generate a loss investigation (if one is needed).
VOA = Vessel On Arrival = The field "TCV Before Discharge" from the worksheet.
ROB = Remaining on Board
TCV = Total Calculated Volume
Outturn = Outturn- As a verb - to outturn: to discharge the cargo. As a noun - The outturn: the actual list of cargo discharged from a ship or from a container.
The formula it uses is:
Outturn TCV - (TCV before discharge - ROB) = Difference
The difference is then calculated as a percentage of the Outturn TCV:
Difference / Outturn TCV = %
The %age is then compared to a threshold provided by the customer and typically set during system setup. If it exceeds that threshold, then a loss investigation will be raised.