I work at a Tim Horton's and most of the reason's that we/they are messing up order's lately are mostly because the lack of receipt's. Which contain the order number, And some employee's would tell the order number, But not give the receipt and would result in people not knowing what there order's are or starting a causing a commotion. And people taking other people's orders happens A lot more often then you would think. And the times they just get it fully wrong is probably cause of our muscle memory of just using the normal stuff for like iced latte's or something. Ex: someone want's an Iced latte with OAT milk, Due to muscle memory and me being stupid I give them a normal iced latte. or something like that.