In this refinery operations simulation each second the ship on the row unloads its oil to the big tank if it is possible. It means, there has to be enough space to take row oil into the big tank. If not, it waits until there is. Then, at the same second that the row oil unloads, the oil in big tank is processed in refinery. %30 of row oil that poured to the big tank becomes fuel oil and then unloaded to fuel oil tank. Then, the rest of row oil becomes benzine and unloaded to benzine tank. After that, tanks are unloaded the tankers that are waiting in the line.