If your application is minimized and you still want to alert user, you should flash icon on taksbar instead of bring your application to front. Here is how to do it…
All you need is this small piece of code. Using the function FlashWindow (from Windows unit), you can blink your apllication button on taskbar (standard system color is used).
procedure TForm1.Button1Click(Sender: TObject);
begin
FlashWindow(Application.Handle, true);
end;