function [Routes,Eta,Tau,Multi_Days_Score,Multi_Days_Route,Delta]= Optimization(Routes,Eta,Tau,Delta,Multi_Days_Route)
    global Trip_Length
    global Iterations
    global Ants_No
    global Group_Size
    
    
    Multi_Days_Score = zeros(Trip_Length,1,Group_Size);
    Multi_Days_Route = cell(Trip_Length,1,Group_Size);
    for day = 1: Trip_Length
        Best_Score = zeros(Group_Size,1);
        Best_Route = cell(Group_Size,1);
        for i = 1 : Iterations
            for Ant_k =1 : Ants_No
                while ~Valid(Ant_k, Routes)
                    [Routes,Eta,Tau,Multi_Days_Route] = Route(Ant_k,Routes,Eta,Tau,Multi_Days_Route);
                end
                [Current_Score,A_Scores,C_Scores,W_Scores]= Score_Calculate(Ant_k,Routes);
                for user =1: Group_Size
                    if Current_Score(user,1) > Best_Score(user,1)
                        Multi_Days_Score(day,1,user) = A_Scores(user,1);
                        Multi_Days_Score(day,2,user) = C_Scores(user,1);
                        Multi_Days_Score(day,3,user) = W_Scores(user);
                        Multi_Days_Route{day,1,user} = Routes.Path{Ant_k,1,user};
                        
                        
                        Best_Score(user,1) = Current_Score(user,1);
                        Best_Route{user,1} = Routes.Path{Ant_k,1,user};
                    end
                end
                [Delta,Tau] = Local_Update_Pheromones(Ant_k,Routes,Current_Score,Delta,Tau);
            end
            Tau = Global_Update_Pheromones(Tau,Delta);
            Probability.Node = zeros(1,1,Group_Size);
            Probability.Users = cell(1,1,Group_Size);
            Probability.Percentage = zeros(1,1,Group_Size);
            
            [Tau,Delta,Eta,Routes,Best_Score] = Setup_Data();
        end
        
       
    end
end