Single Minute Exchange of Die is a Toyota developed system that helped them to change the dies from a half of the day to about 10 min. To achieve this, they had to implement many changes. However, most of the changes didnt cost much and didnt take a lot of time. Many of the activities are in fact just organizational, mind set change and understanding of the needs.
As for the injection molding companies, its quite usual that it takes 60-120 mins to change a tool (from last good to first good), which is too long as its possible to change the tools in 20-25 mins without need of very much investment . By reduction of the tool change time the companies can save a lot of money and capacity of the molding machines. Imagine, you change a tool in 60 min and after the change you will change the tool in 30 min. In case you do 20 tool changes per day, you get 30×20 min of time saving which is 600 mins => 10 hours of machine capacity. This is enormous save of money and in fact, its not even as much expensive as many managers/CEOs think. It just needs someone experienced in this kind of activity and “small” amount of money (mainly for the standardization and equipment availability at the injection molding machines).