Storing data iteratively in a parameter

I am trying to develop a model and store the output iteratively. The code I have written is given below. I am trying to store the output “poFGAllocation(sr,d,p,b,f,n,a,s,l)” iteratively. Model is running and showing optimal solution. However, the output parameter returns empty dataframe. 

pLoopCount is a parameter with initial value 1. 

while (pCardFG > 0) do
	for sr do
		pr_Read_Input_Data;
		solve mpMaximizeWagonCap where MIP_absolute_optimality_tolerance = 0.05;
		showProgressWindow();
		!vFGAllocationTonsLoop1(xy,sr,d,p,b,f,n,a,s,l) := vFGAllocationTonsLoop(sr,d,p,b,f,n,a,s,l);
		poFGAllocation(sr,d,p,b,f,n,a,s,l) := vFGAllocationTons(d,p,b,f,n,a,s,l);
		sFGLoaded := sFGLoaded + {f| sum[(d,p,b,n,a,s,l),vFGAllocationTons(d,p,b,f,n,a,s,l)] >= 0.99};
		sFG_ID := sFG_ID - {f| sum[(d,p,b,n,a,s,l),vFGAllocationTons(d,p,b,f,n,a,s,l)] >= 0.95};	
	endfor;
	pr_Write_Output_Data;
	execute("cmd.exe /k 1interProcessData.bat", wait: 1, minimized:1);
	pLoopCount += 1; 
endwhile;

Kindly help if I am doing anything wrong.