Ballast Water Management Decision Support System - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 227

Fig. 3 DSS model high level elements (Enhanced after David 2007 ). BW Ballast Water, BWDA
Ballast Water Discharge Assessment, PSA Port State Authority, PSC Port State Control. Yellow box
is Situation (1) - vessel is on the way to port of call, BWM enabled; orange box is Situation (2) -
vessel is on the way to port of call or even entered the port, no BWM enabled and the port entry
permit is not yet issued; light blue box is Situation (3) - vessel is in the port, the port entry permit
is issued; and grey box is Situation (4) - vessel has left port of call